Segment Information - Reconciliation of Total Segment Profit to Operating Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting [Abstract]
Total segment profit	$ 487,907	$ 367,898	$ 386,259
Amortization	53,092	66,428	62,152
Unallocated general and administrative expenses	39,370	62,192	31,418
Operating income	395,445	239,278	292,689
Interest expense	48,600	46,962	34,094
Interest income	786	4,652	3,839
Other (income) expense, net	(6,656)	(121,081)	8,002
Income before income tax expense	$ 354,287	$ 318,049	$ 254,432