Annual report pursuant to Section 13 and 15(d)

Schedule of Restricted Cash and Cash Equivalents (Details)

v3.8.0.1
Schedule of Restricted Cash and Cash Equivalents (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Restricted Cash and Cash Equivalents Items [Line Items]      
Restricted cash $ 635,836 $ 408,052 $ 262,562
Restricted Cash and Cash Equivalents Held for Securities Trading Activity [Member]      
Restricted Cash and Cash Equivalents Items [Line Items]      
Restricted cash 27,050 26,050  
Restricted Cash and Cash Equivalents Held for Derivatives Trading Activity [Member]      
Restricted Cash and Cash Equivalents Items [Line Items]      
Restricted cash 191,421 218,896  
Restricted Cash and Cash Equivalents Pledged as Restricted Collateral for Borrowings [Member]      
Restricted Cash and Cash Equivalents Items [Line Items]      
Restricted cash 417,018 162,759  
Restricted Cash and Cash Equivalents Held by Counterparties [Member]      
Restricted Cash and Cash Equivalents Items [Line Items]      
Restricted cash 635,489 407,705  
Restricted Cash and Cash Equivalents for Lease [Member]      
Restricted Cash and Cash Equivalents Items [Line Items]      
Restricted cash $ 347 $ 347