Amounts Recognized in AOCI (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, net of income tax	$ 5,504,105
Other comprehensive income (loss), Pretax amount	18,047	$ 32,464	$ 4,419
Other comprehensive income (loss), Income tax effect	(1,820)	(4,813)	(8,905)
Total other comprehensive income (loss), net of tax	16,227	27,651	(4,486)
Ending balance, net of income tax	6,317,146	5,504,105
Net Unrealized Gains (Losses) on Effective Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, net of income tax	(17)	2,980
Other comprehensive income (loss), Pretax amount	0	(3,925)
Other comprehensive income (loss), Income tax effect	0	928
Total other comprehensive income (loss), net of tax	0	(2,997)
Ending balance, net of income tax	(17)	(17)	2,980
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, net of income tax	39,568	15,375
Other comprehensive income (loss), Pretax amount	13,619	27,886
Other comprehensive income (loss), Income tax effect	(749)	(3,693)
Total other comprehensive income (loss), net of tax	12,870	24,193
Ending balance, net of income tax	52,438	39,568	15,375
Minimum Pension Liability
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, net of income tax	(7,658)	(14,113)
Other comprehensive income (loss), Pretax amount	4,428	8,503
Other comprehensive income (loss), Income tax effect	(1,071)	(2,048)
Total other comprehensive income (loss), net of tax	3,357	6,455
Ending balance, net of income tax	(4,301)	(7,658)	(14,113)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, net of income tax	31,893	4,242
Ending balance, net of income tax	$ 48,120	$ 31,893	$ 4,242