Derivative Instruments and Hedging Activities - Schedule of Gross Amounts of Derivative Assets and Derivative Liabilities (Detail) - Not Designated as Hedging Instruments - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Derivative Asset [Abstract]
Gross amounts recognized		$ 15,281	$ 11,295
Gross amounts offset		0	0
Net amounts presented in the Consolidated Balance Sheets		15,281	11,295
Gross amounts not offset	[1]	0	0
Net Amount		15,281	11,295
Derivative Liability [Abstract]
Gross amounts recognized		15,165	11,276
Gross amounts offset		0	0
Net amounts presented in the Consolidated Balance Sheets		15,165	11,276
Gross amounts not offset	[1]	(13,293)	(12,573)
Net Amount		$ 1,872	$ (1,297)

[1] Amounts represent posted collateral.