Stock-based Compensation Plans - Additional Information 4 (Detail) - USD ($) shares in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation plan vesting period	3 years
Deferred compensation plan	$ (19,811,000)	$ 8,537,000
Shares held in rabbi trust total	7.1		6.1
Vested shares held in rabbi trust	5.3		5.0
Post-Retirement Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Estimated prior service cost amortized from accumulated other comprehensive income into general and administrative expense	$ 90,000	$ 90,000