Derivatives and Hedging Activities (Interest Rate Swaps Subject to Master Netting Agreements) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross Amounts Recognized, Derivative assets	$ 363	$ 3,830
Gross Amounts Recognized, Derivative liabilities	(134,217)	(69,135)
Gross Amounts Recognized, Derivative assets and liabilities	(133,854)	(65,305)
Gross Amounts Offset in Balance Sheet, Derivative assets	0	0
Gross Amounts Offset in Balance Sheet, Derivative liabilities	0	0
Gross Amounts Offset in Balance Sheet, Derivative assets and liabilities	0	0
Net Amounts Presented in Balance Sheet, Derivative assets	363	3,830
Net Amounts Presented in Balance Sheet, Derivative liabilities	(134,217)	(69,135)
Net Amounts Presented in Balance Sheet, Derivative assets and liabilities	(133,854)	(65,305)
Gross Amounts Not Offset in Balance Sheet
Derivative Instruments, Derivative assets	(363)	(3,605)
Derivative Instruments, Derivative liabilities	363	3,605
Derivative Instruments, Derivative assets and liabilities	0	0
Collateral Pledged, Derivative assets	0	0
Collateral Pledged, Derivative liabilities	133,854	65,530
Collateral Pledged, Derivative assets and liabilities	133,854	65,530
Net Amount, Derivative assets	0	225
Net Amount, Derivative liabilities	0	0
Net Amount, Derivative assets and liabilities	$ 0	$ 225