Employee Benefit Plans (Defined Benefit Pension Plans Recognized as Component of Other Comprehensive Income) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	$ (6,199)	$ 1,979	$ (2,223)
Deferred tax (expense) benefit	1,302	(416)	466
Other comprehensive income (loss), net of tax	$ (4,897)	$ 1,563	$ (1,757)