Income Taxes (Schedule of Unrecognized Tax Benefits Roll Forward) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 5,651	$ 5,787
Decrease for prior year positions	0	(120)
Decreases relating to settlements with taxing authorities and other	(81)	(16)
Balance at end of period	$ 5,570	$ 5,651