Quarterly report pursuant to Section 13 or 15(d)

Information by Business Segment (Details)

v2.4.0.6
Information by Business Segment (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 9 Months Ended
Sep. 30, 2012
segments
Sep. 30, 2011
Sep. 30, 2012
segments
Sep. 30, 2011
Dec. 31, 2011
Segment Reporting [Abstract]          
Number of primary office property segments 10   10    
Segment financial information for real estate operations          
Revenues from real estate operations $ 121,264 $ 125,129 $ 370,536 $ 368,376  
Property operating expenses 45,016 47,994 138,562 142,819  
NOI from real estate operations 76,248 77,135 231,974 225,557  
Additions to long-lived assets 61,803 43,843 76,107 79,060  
Transfers from non-operating properties 28,146 31,845 129,348 77,056  
Segment assets 3,597,656 3,965,392 3,597,656 3,965,392 3,867,524
Operating Segment Total
          
Segment financial information for real estate operations          
Segment assets 2,836,547 3,055,750 2,836,547 3,055,750  
Baltimore and Washington Corridor
          
Segment financial information for real estate operations          
Revenues from real estate operations 55,799 54,744 167,726 160,856  
Property operating expenses 19,069 19,628 58,285 58,669  
NOI from real estate operations 36,730 35,116 109,441 102,187  
Additions to long-lived assets 4,454 3,410 9,393 14,631  
Transfers from non-operating properties 12,431 17,625 42,488 43,648  
Segment assets 1,187,700 1,200,407 1,187,700 1,200,407  
Northern Virginia
          
Segment financial information for real estate operations          
Revenues from real estate operations 20,363 18,640 57,974 55,359  
Property operating expenses 7,313 7,278 21,889 22,144  
NOI from real estate operations 13,050 11,362 36,085 33,215  
Additions to long-lived assets 54,781 5,420 57,161 10,234  
Transfers from non-operating properties 12,979 7 12,979 4  
Segment assets 535,521 485,450 535,521 485,450  
San Antonio
          
Segment financial information for real estate operations          
Revenues from real estate operations 8,125 7,701 23,563 22,453  
Property operating expenses 4,337 3,824 12,177 10,775  
NOI from real estate operations 3,788 3,877 11,386 11,678  
Additions to long-lived assets 0 0 259 0  
Transfers from non-operating properties 0 87 464 846  
Segment assets 119,752 115,001 119,752 115,001  
Washington, DC - Capitol Riverfront
          
Segment financial information for real estate operations          
Revenues from real estate operations 4,389 4,507 12,515 13,349  
Property operating expenses 1,959 1,808 5,585 5,092  
NOI from real estate operations 2,430 2,699 6,930 8,257  
Additions to long-lived assets 414 (227) 116 585  
Transfers from non-operating properties 0 0 0 0  
Segment assets 106,090 112,865 106,090 112,865  
St. Mary's and King George Counties
          
Segment financial information for real estate operations          
Revenues from real estate operations 4,085 3,508 12,436 10,606  
Property operating expenses 1,292 1,143 3,689 3,118  
NOI from real estate operations 2,793 2,365 8,747 7,488  
Additions to long-lived assets 355 197 815 1,038  
Transfers from non-operating properties 24 0 218 0  
Segment assets 97,977 84,781 97,977 84,781  
Greater Baltimore
          
Segment financial information for real estate operations          
Revenues from real estate operations 11,918 18,193 41,954 53,651  
Property operating expenses 4,662 7,553 16,357 23,238  
NOI from real estate operations 7,256 10,640 25,597 30,413  
Additions to long-lived assets 1,055 2,034 5,390 14,237  
Transfers from non-operating properties 99 343 493 8,184  
Segment assets 283,996 438,041 283,996 438,041  
Suburban Maryland
          
Segment financial information for real estate operations          
Revenues from real estate operations 2,371 5,648 12,680 16,582  
Property operating expenses 1,058 1,975 5,461 6,814  
NOI from real estate operations 1,313 3,673 7,219 9,768  
Additions to long-lived assets 36 4,126 1,219 7,631  
Transfers from non-operating properties (88) 11 793 396  
Segment assets 53,395 145,677 53,395 145,677  
Colorado Springs
          
Segment financial information for real estate operations          
Revenues from real estate operations 6,278 6,037 18,880 17,869  
Property operating expenses 2,528 2,465 7,107 6,788  
NOI from real estate operations 3,750 3,572 11,773 11,081  
Additions to long-lived assets 548 1,369 1,334 3,190  
Transfers from non-operating properties 315 209 2,611 211  
Segment assets 173,918 212,415 173,918 212,415  
Greater Philadelphia
          
Segment financial information for real estate operations          
Revenues from real estate operations 2,541 1,701 7,171 5,315  
Property operating expenses 736 417 2,083 1,180  
NOI from real estate operations 1,805 1,284 5,088 4,135  
Additions to long-lived assets 195 694 285 690  
Transfers from non-operating properties 1,843 48 11,233 3,598  
Segment assets 66,301 101,432 66,301 101,432  
Other
          
Segment financial information for real estate operations          
Revenues from real estate operations 3,589 3,167 10,977 8,567  
Property operating expenses 716 849 2,201 2,409  
NOI from real estate operations 2,873 2,318 8,776 6,158  
Additions to long-lived assets (35) 26,769 124 26,773  
Transfers from non-operating properties 548 0 394 0  
Segment assets 111,426 115,777 111,426 115,777  
Wholesale Data Center
          
Segment financial information for real estate operations          
Revenues from real estate operations 1,806 1,283 4,660 3,769  
Property operating expenses 1,346 1,054 3,728 2,592  
NOI from real estate operations 460 229 932 1,177  
Additions to long-lived assets 0 51 11 51  
Transfers from non-operating properties (5) 13,515 57,675 20,169  
Segment assets $ 100,471 $ 43,904 $ 100,471 $ 43,904