Derivatives and Hedging Activities (Offsetting Disclosure for Derivative Contracts) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative asset, fair value, gross	$ 12,974	$ 5,742	$ 2,844
offsetting disclosure, offset amount, derivative asset, fair value, gross	0	0	0
offsetting disclosure, net amount, derivative asset, falir value	12,974	5,742	2,844
offseting disclosure, netting adjustment, derivative asset, fair value	(20)	(324)	(2,828)
offsetting disclosure, collateral value, derivative asset	(266)	(162)	(16)
offsetting disclosure, net amount total, derivative asset, fair value	12,688	5,256	0
offsetting disclosure, derivative liability, fair value, gross	65,190	54,725	52,270
offsetting disclosure, offset amount, derivative liability, fair value, gross	0	0	0
offsetting disclosure, net amount, derivative liability, falir value	65,190	54,725	52,270
offseting disclosure, netting adjustment, derivative liability, fair value	(20)	(324)	(2,828)
offsetting disclosure, collateral value, derivative liability	(65,170)	(54,401)	(49,442)
offsetting disclosure, net amount total, derivative liability, fair value	0	0	0
Designated as Hedging Instrument | Interest Rate Swap
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative asset, fair value, gross	12,688	5,256
offsetting disclosure, offset amount, derivative asset, fair value, gross	0	0
offsetting disclosure, net amount, derivative asset, falir value	12,688	5,256
offseting disclosure, netting adjustment, derivative asset, fair value	0	0
offsetting disclosure, collateral value, derivative asset	0	0
offsetting disclosure, net amount total, derivative asset, fair value	12,688	5,256
offsetting disclosure, derivative liability, fair value, gross	6,063	6,683	10,392
offsetting disclosure, offset amount, derivative liability, fair value, gross	0	0	0
offsetting disclosure, net amount, derivative liability, falir value	6,063	6,683	10,392
offseting disclosure, netting adjustment, derivative liability, fair value	0	0	0
offsetting disclosure, collateral value, derivative liability	(6,063)	(6,683)	(10,392)
offsetting disclosure, net amount total, derivative liability, fair value	0	0	0
Not Designated as Hedging Instrument | Interest Rate Swap
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative asset, fair value, gross	67	352	2,811
offsetting disclosure, offset amount, derivative asset, fair value, gross	0	0	0
offsetting disclosure, net amount, derivative asset, falir value	67	352	2,811
offseting disclosure, netting adjustment, derivative asset, fair value	(67)	(352)	(2,811)
offsetting disclosure, collateral value, derivative asset	0	0	0
offsetting disclosure, net amount total, derivative asset, fair value	0	0	0
offsetting disclosure, derivative liability, fair value, gross	59,080	48,014	41,861
offsetting disclosure, offset amount, derivative liability, fair value, gross	0	0	0
offsetting disclosure, net amount, derivative liability, falir value	59,080	48,014	41,861
offseting disclosure, netting adjustment, derivative liability, fair value	(67)	(352)	(2,811)
offsetting disclosure, collateral value, derivative liability	(59,013)	(47,662)	(39,050)
offsetting disclosure, net amount total, derivative liability, fair value	0	0	0
Not Designated as Hedging Instrument | Foreign Exchange Contract
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative asset, fair value, gross	219	134	33
offsetting disclosure, offset amount, derivative asset, fair value, gross	0	0	0
offsetting disclosure, net amount, derivative asset, falir value	219	134	33
offseting disclosure, netting adjustment, derivative asset, fair value	47	28	(17)
offsetting disclosure, collateral value, derivative asset	(266)	(162)	(16)
offsetting disclosure, net amount total, derivative asset, fair value	0	0	0
offsetting disclosure, derivative liability, fair value, gross	47	28	17
offsetting disclosure, offset amount, derivative liability, fair value, gross	0	0	0
offsetting disclosure, net amount, derivative liability, falir value	47	28	17
offseting disclosure, netting adjustment, derivative liability, fair value	47	28	(17)
offsetting disclosure, collateral value, derivative liability	(94)	(56)	0
offsetting disclosure, net amount total, derivative liability, fair value	$ 0	$ 0	$ 0