Fair Value Measurements - Assets and Liabilities at Fair Value on Recurring Basis (Parenthetical) (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Sales of equity securities	$ 0
Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities held in fair value	8,500,000	$ 13,200,000
Other Income Expense [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net unrealized gains on equity securities	$ 4,600,000