Schedule of Restricted Stock Unit Awards Aggregate Intrinsic Value (Detail) - Restricted Stock Units - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award
Vested	$ 46,110	$ 63,688	$ 40,649
Outstanding	$ 154,752	$ 77,015	$ 132,875
Expected to vest	$ 152,374	$ 77,187	$ 130,594