Business, Basis of Presentation and Summary of Significant Accounting Policies - Optimizing Capital Structure (Details)				1 Months Ended						12 Months Ended
	Jan. 19, 2022 $ / shares	Feb. 21, 2020 USD ($) $ / shares shares	Mar. 07, 2019 USD ($) $ / shares shares	Jan. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) shares	Oct. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($) shares	Dec. 31, 2018 shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($) shares	Nov. 30, 2021 shares	Sep. 30, 2021 USD ($)	Sep. 13, 2021 USD ($)	Mar. 31, 2021 USD ($)	Mar. 10, 2021 USD ($)	Dec. 23, 2020 USD ($)	Jun. 30, 2020 USD ($)	Jun. 23, 2020 USD ($)
Business Acquisition [Line Items]
Common stock issued												$ 29,218,000
Payments to Acquire Investments										$ 530,832,000	$ 409,074,000	$ 489,124,000
Investment, Maximum Target Size					$ 200,000,000					$ 200,000,000
Marstone, Inc
Business Acquisition [Line Items]
Payments to acquire equity method investments					1,000,000		$ 2,500,000
Raistone Financial Corp
Business Acquisition [Line Items]
Payments to acquire equity method investments						$ 2,500,000
JAM FINTOP Blockchain Fund
Business Acquisition [Line Items]
Payments to Acquire Investments					5,400,000
JAM FINTOP Blockchain Fund | If Investment Increase to Maximum Size
Business Acquisition [Line Items]
Payments to Acquire Investments					$ 9,800,000
Class B
Business Acquisition [Line Items]
Treasury stock, acquired (in shares) | shares										565,232
Treasury stock acquired (in dollars per share) | $ / shares										$ 16.92
Treasury stock acquired										$ 9,600,000
Common stock, shares outstanding (in shares) | shares					0			9,036,352		0	9,036,352
Class B | Clean-Up Merger
Business Acquisition [Line Items]
Common stock, shares outstanding (in shares) | shares													0
Class A
Business Acquisition [Line Items]
Common stock, shares outstanding (in shares) | shares					35,883,320			28,806,344		35,883,320	28,806,344
Dividends, declared (in dollars per share) | $ / shares										$ 0.06
Class A | Subsequent Event
Business Acquisition [Line Items]
Treasury stock, acquired (in shares) | shares				652,118
Treasury stock acquired (in dollars per share) | $ / shares				$ 33.96
Treasury stock acquired				$ 21,100,000
Dividends, declared (in dollars per share) | $ / shares	$ 0.09
Common Stock | Class B
Business Acquisition [Line Items]
Common stock issued								$ 54,000,000
Stock repurchase program, authorized amount																$ 40,000,000
Treasury stock, acquired (in shares) | shares		932,459	2,112,321						1,400,000
Treasury stock acquired (in dollars per share) | $ / shares		$ 16.00	$ 13.48
Treasury stock acquired		$ 15,200,000	$ 28,500,000
Common stock, shares outstanding (in shares) | shares					0			9,036,352	16,330,917	0	9,036,352	14,218,596
Common Stock | Class B | Maximum
Business Acquisition [Line Items]
Stock repurchase program, authorized amount																	$ 40,000,000	$ 50,000,000
Common Stock | Class B | Clean-Up Merger
Business Acquisition [Line Items]
Stock, conversion ratio													0.95	0.95
Common Stock | Class A
Business Acquisition [Line Items]
Common stock issued												$ 213,000
Stock repurchase program, authorized amount														$ 50,000,000
Common stock, shares outstanding (in shares) | shares					35,883,320			28,806,344	26,851,832	35,883,320	28,806,344	28,927,576
Common Stock | Class A | Maximum
Business Acquisition [Line Items]
Stock repurchase program, authorized amount															$ 50,000,000
Common Stock | Class A | Clean-Up Merger | Maximum
Business Acquisition [Line Items]
Post merger, number of shares owned (in shares) | shares													100
Common Stock | Class A | Clean-Up Merger | Minimum
Business Acquisition [Line Items]
Post merger, percent of outstanding shares owned													8.90%
Senior Notes | 5.75% Senior Notes due 2025
Business Acquisition [Line Items]
Face amount																			$ 60,000,000	$ 60,000,000
Interest rate, stated percentage																			5.75%	5.75%