Accumulated Other Comprehensive Income (Loss) - Changes in Balances of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017		Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 231,963	[1]	$ 240,201
Other comprehensive income (loss) before reclassifications	1,958		891
Amounts reclassified to net income (loss)	(201)		194
Other comprehensive income (loss)	1,757		1,085
Ending balance	272,944		231,168
Unrealized Gain (Loss) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,065)		(1,021)
Other comprehensive income (loss) before reclassifications	1,930		722
Amounts reclassified to net income (loss)	(201)		194
Other comprehensive income (loss)	1,729		916
Ending balance	664		(105)
Unrealized Gain (Loss) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(413)		(310)
Other comprehensive income (loss) before reclassifications	28		169
Amounts reclassified to net income (loss)	0		0
Other comprehensive income (loss)	28		169
Ending balance	(385)		(141)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,478)		(1,331)
Ending balance	$ 279		$ (246)

[1] The Condensed Consolidated Balance Sheet as of December 31, 2016 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.