Incentive Plans - Summary of Impact of LFI and Other Similar Deferred Compensation Arrangements (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share Based Compensation [Abstract]
Amortization, net of forfeitures	$ 25,897	$ 23,325	$ 95,322	$ 85,469
Change in the fair value of underlying investments	11,261	1,764	15,427	22,118
Total	$ 37,158	$ 25,089	$ 110,749	$ 107,587

Amount of expense recognized from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments), awarded to key employees or individuals. Excludes amount related to plans that cover generally all employees (for example, but not limited to, qualified pension plans).

No definition available.

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Balance Type:	debit
Period Type:	duration