Stock Transactions and Unit Redemptions - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Mar. 08, 2021	Mar. 09, 2018	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Aug. 03, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Stock repurchase program and unit redemption remaining authorized amount			$ 322,835		$ 322,835
CF & Co
Class of Stock [Line Items]
Common stock, issued during the period (in shares)			0	0		200,000
Aggregate proceeds from issuance of common stock						$ 700
Class B Common Stock
Class of Stock [Line Items]
Common stock, issued during the period (in shares)			0	0	0	0
Common stock, shares outstanding (in shares)			45,884,000		45,884,000			45,884,000
Common stock, shares issued (in shares)			45,884,000		45,884,000			45,884,000
Common stock value			$ 459		$ 459			$ 459
Class A Common Stock
Class of Stock [Line Items]
Common stock, issued during the period (in shares)			100,128	91,034	366,043	339,617
Common stock, shares outstanding (in shares)			333,408,000		333,408,000			323,018,000
Common stock, shares issued (in shares)			426,015,000		426,015,000			373,545,000
Common stock value			$ 4,260		$ 4,260			$ 3,735
Aggregate proceeds from issuance of common stock	$ 300,000
Company's repurchase and additional redemption authority amount							$ 400,000
Stock repurchase program and unit redemption remaining authorized amount			$ 322,800		$ 322,800
New CEO Program | CF & Co
Class of Stock [Line Items]
Common stock, issued during the period (in shares)			0		0
Payment percentage of the gross proceeds from the sale of shares		2.00%
New CEO Program | Class A Common Stock
Class of Stock [Line Items]
Maximum amount under the controlled equity offering program		$ 300,000
Common stock, shares issued (in shares)			17,600,000		17,600,000
Common stock value			$ 210,800		$ 210,800