Derivative Instruments and Hedging Activities - Gains and Losses, Net of Tax, Related to Derivative Instruments Designated as Cash Flow Hedges Included in Accumulated Other Comprehensive Income, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ (1,572)	$ 3,320