Income Taxes - Changes In Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unrecognized tax benefits
Unrecognized tax benefits—beginning balance	$ 13,300	$ 12,800	$ 18,100
Gross decreases—prior period tax positions	(8,600)	0	(1,000)
Gross increases—current period tax positions	800	500	0
Settlements with taxing authorities	(4,000)	0	(4,300)
Unrecognized tax benefits—ending balance	$ 1,500	$ 13,300	$ 12,800