Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments and Hedging Activities Credit Risk - Counterparty Exposure (Details)

v3.4.0.3
Derivative Instruments and Hedging Activities Credit Risk - Counterparty Exposure (Details) - USD ($)
$ in Thousands
Mar. 31, 2016
Dec. 31, 2015
Credit Derivatives [Line Items]    
Collateral Securities Repledged, Delivered, or Used $ (2,220)  
Collateral Already Posted, Aggregate Fair Value 232,054  
Derivative Financial Instruments, Assets [Member]    
Credit Derivatives [Line Items]    
Derivative, Fair Value, Net 197,847 $ 271,509
Derivative Financial Instruments, Liabilities [Member]    
Credit Derivatives [Line Items]    
Derivative, Fair Value, Net $ (77,038) $ (7,285)