Leases (Details 3) - USD ($) $ in Thousands  | 
Jun. 30, 2019  | 
Dec. 31, 2018  | 
|---|---|---|
| Lessee, Lease, Description [Line Items] | ||
| Finance right-of-use assets | $ 41,748 | |
| Total right-of-use assets | 69,182 | |
| Property - operating lease liabilities | 16,640 | |
| Property - finance lease liabilities | 1,228 | |
| Total lease liabilities | 17,868 | $ 90,184 | 
| Properties | ||
| Lessee, Lease, Description [Line Items] | ||
| Property - operating right-of-use assets | 27,434 | 0 | 
| Finance right-of-use assets | 40,476 | 0 | 
| Property - operating lease liabilities | 16,640 | $ 0 | 
| Property - operating right-of-use assets | Properties | ||
| Lessee, Lease, Description [Line Items] | ||
| Property - operating right-of-use assets | 27,434 | |
| Property - finance right-of-use assets | Properties | ||
| Lessee, Lease, Description [Line Items] | ||
| Finance right-of-use assets | 40,476 | |
| Prepaid expenses and other assets, net | Vehicles and Office Equipment | ||
| Lessee, Lease, Description [Line Items] | ||
| Finance right-of-use assets | $ 1,272 | 
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- Definition Lease Liabilities No definition available. 
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- Definition Lease, Right-of-Use Assets No definition available. 
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- Definition Present value of lessee's discounted obligation for lease payments from finance lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of lessee's right to use underlying asset under finance lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of lessee's right to use underlying asset under operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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