Other Comprehensive Income (Loss )- Components of Accumulated Other Comprehensive Loss, Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Equity [Abstract]
Foreign Currency Translation Adjustments, Beginning balance		$ (566)
Foreign currency translation adjustments, net of tax	$ 381	(294)
Foreign Currency Translation Adjustments, Ending balance	(860)	(860)
Net Unrealized Gain (Loss) on Investment, Beginning balance		15,882
Unrealized gain (loss) on investment, net of tax	4,885	(1,051)
Net Unrealized Gain (Loss) on Investment, Ending balance	14,831	14,831
Net Unrealized Losses on Derivatives, Beginning balance		(380)
Unrealized loss on cash flow hedging instruments, net of tax	(243)	(3,633)
Net Unrealized Losses on Derivatives, Ending balance	(4,013)	(4,013)
Accumulated Other Comprehensive Income (Loss), Beginning balance		14,936
Accumulated Other Comprehensive (Income) Loss, Current period change	5,023	(4,978)
Accumulated Other Comprehensive Income (Loss), Ending balance	$ 9,958	$ 9,958