Financial Derivatives and Hedging Activities - Fair Value Amounts Recorded as Component of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Balance at January 1,	$ 3,282	$ (1,296)
Deferred gains on cash flow hedges	1,100	2,223
Reclassified to earnings	(4,595)	1,227
Balance at September 30,	$ (213)	$ 2,154