Accumulated Other Comprehensive Income (Loss) - Summary of Components of AOCI (Detail) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, Beginning	$ 348,275	$ 183,456	$ 167,273
Other comprehensive income (loss) before reclassifications	(1,600)	2,200	1,800
Income tax (expense) benefit	300	(1,800)	(700)
Amounts reclassified from AOCI		2,500
Total other comprehensive income (loss)	(1,352)	2,917	1,138
Balance, Ending	332,732	348,275	183,456
Foreign Currency Translation
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, Beginning	(100)
Other comprehensive income (loss) before reclassifications	(300)	(100)
Total other comprehensive income (loss)	(300)	(100)
Balance, Ending	(400)	(100)
Marketable Securities
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss) before reclassifications	(1,300)
Income tax (expense) benefit	300
Total other comprehensive income (loss)	(1,000)
Balance, Ending	(1,000)
Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, Beginning		(3,000)	(4,100)
Other comprehensive income (loss) before reclassifications		2,300	1,800
Income tax (expense) benefit		(1,800)	(700)
Amounts reclassified from AOCI		2,500
Total other comprehensive income (loss)		3,000	1,100
Balance, Ending			(3,000)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, Beginning	(60)	(2,977)	(4,115)
Balance, Ending	$ (1,412)	$ (60)	$ (2,977)