Debt - Short-Term Borrowings (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 26, 2021	Oct. 25, 2021
Short-term Debt [Line Items]
Annualized interest rate	0.29%	0.27%
Letters of credit outstanding	$ 125,000	$ 135,000		$ 135,000	$ 125,000
Remaining amount available under credit line	294,967	360,000
Average balance outstanding during period	$ 311,049	$ 318,409	$ 288,684
Daily-weighted average interest rate (annualized)	0.23%	1.50%	2.62%
Maximum daily amount outstanding during period	$ 465,033	$ 482,000	$ 385,000
Short-term Debt
Short-term Debt [Line Items]
Balance at end of period (at par value)	$ 330,033	$ 255,000