Comprehensive Income Attributable to Noncontrolling Shareholders' Interests (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Net income attributable to noncontrolling shareholders' interests	$ 1,115	$ 1,913	$ 3,977
Other comprehensive income (loss):
Currency translation adjustments	2,279	795	(2,237)
Comprehensive income attributable to noncontrolling shareholders’ interests	$ 3,394	$ 2,708	$ 1,740