Derivative Instruments and Hedging Activities - Fair Value of Offsetting Derivatives (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		$ 40,333	$ 16,233
Less: amounts offset in the Consolidated Statements of Financial Condition		0	0
Net amount presented in the Consolidated Statements of Financial Condition	[1]	40,333	16,233
Offsetting derivative positions		(17,321)	(4,791)
Cash collateral pledged		0	0
Derivative Asset, Net credit exposure		23,012	11,442
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		40,833	21,039
Less: amounts offset in the Consolidated Statements of Financial Condition		0	0
Net amount presented in the Consolidated Statements of Financial Condition	[1]	40,833	21,039
Offsetting derivative positions		(17,321)	(4,791)
Cash collateral pledged		(23,512)	(16,248)
Derivative Liability, Net credit exposure		$ 0	$ 0

[1] Included in other assets or other liabilities in the Consolidated Statements of Financial Condition.