Stock Transactions and Unit Redemptions - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended
	Mar. 08, 2021	Mar. 09, 2018	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Aug. 01, 2018
Class of Stock [Line Items]
Stock repurchase program and unit redemption remaining authorized amount			$ 114,584		$ 114,584
CF & Co
Class of Stock [Line Items]
Common stock, issued during the period (in shares)			0	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)			3,542	176,920	265,915	248,583
Common stock, shares outstanding (in shares)			348,795,000		348,795,000		323,018,000
Common stock, shares issued (in shares)			416,914,000		416,914,000		373,545,000
Common stock value			$ 4,169		$ 4,169		$ 3,735
Aggregate proceeds from issuance of common stock	$ 300,000
Company's repurchase and additional redemption authority amount								$ 300,000
Stock repurchase program and unit redemption remaining authorized amount			$ 114,600		$ 114,600
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
Aggregate proceeds from issuance of common stock	$ 89,200