Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 32,468	$ 24,779	$ 70,405	$ 55,157
Other comprehensive income (loss):
Foreign currency translation adjustment	82	82	42	222
Tax provision	(20)	(15)	(12)	(54)
Comprehensive income	$ 32,530	$ 24,846	$ 70,435	$ 55,325