Changes in Accumulated Other Comprehensive Income (Loss) by Component - Changes in Accumulated Other Comprehensive Income (loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	$ (4,114)	$ (2,220)	$ (122)	$ (8,118)
Other comprehensive (loss) before reclassifications	(1,301)	(800)	(5,336)	7,172
Amounts reclassified from accumulated other comprehensive loss to net income	10	0	53	(2,074)
Net current-period other comprehensive (loss)	(1,291)	(800)	(5,283)	5,098
Ending balance	(5,405)	(3,020)	(5,405)	(3,020)
Unrealized Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(1,825)		1,156
Other comprehensive (loss) before reclassifications	598		(2,426)
Amounts reclassified from accumulated other comprehensive loss to net income	10		53
Net current-period other comprehensive (loss)	608		(2,373)
Ending balance	(1,217)		(1,217)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(136)		(14)
Other comprehensive (loss) before reclassifications	(435)		(557)
Amounts reclassified from accumulated other comprehensive loss to net income	0		0
Net current-period other comprehensive (loss)	(435)		(557)
Ending balance	(571)		(571)
Total Unrealized Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(1,961)	(1,598)	1,142	(8,118)
Other comprehensive (loss) before reclassifications	163	(1,226)	(2,983)	7,368
Amounts reclassified from accumulated other comprehensive loss to net income	10	0	53	(2,074)
Net current-period other comprehensive (loss)	173	(1,226)	(2,930)	5,294
Ending balance	(1,788)	(2,824)	(1,788)	(2,824)
Unrealized Loss on Cash Flow Hedge
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(2,153)	(622)	(1,264)	0
Other comprehensive (loss) before reclassifications	(1,464)	426	(2,353)	(196)
Amounts reclassified from accumulated other comprehensive loss to net income	0	0	0	0
Net current-period other comprehensive (loss)	(1,464)	426	(2,353)	(196)
Ending balance	$ (3,617)	$ (196)	$ (3,617)	$ (196)