Financial Derivatives - Deferred Gains (Losses) and Related Taxes on Cash Flow Hedges (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Deferred gains (losses) in AOCI	$ (2,188)	$ 2,221
Tax on deferred gains (losses) in AOCI	(3)	69
Deferred gains (losses) in AOCI, net of taxes	(2,191)	$ 2,290
Deferred gains (losses) expected to be reclassified to "Revenues" from AOCI during the next twelve months	$ (2,188)