Related-Party Transactions - Management Agreement (Details)	1 Months Ended	12 Months Ended
	Apr. 30, 2020 USD ($) shares	Dec. 31, 2021 USD ($) qtr d shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($) shares
Related-Party Transactions
Incentive fee quarters period | qtr		3
Trading days period | d		5
Granted (in shares) | shares		1,708,935
Share-based expense		$ 74,421,000	$ 65,734,000	$ 46,237,000
2017 Manager Equity Plan
Related-Party Transactions
Granted (in shares) | shares		0
S P T Management L L C
Related-Party Transactions
Base management fee		1.50%
Management fee expense	$ 19,100,000	$ 77,900,000	76,600,000	77,000,000
Management fee, shares issuable (in shares) | shares	1,422,143
Base management fee payable		$ 20,300,000	19,200,000
Core earnings period threshold		12 months
Core earnings threshold percentage		8.00%
Core earnings threshold, number of quarters | qtr		12
Core earnings threshold amount		$ 0
Incentive fee calculation amount		$ 0
Incentive Fee, Calculation, Multiplication Factor		20.00%
Rolling period		12 months
Stock value factor		8.00%
Stock ownership limit		9.80%
Accrued incentive fee		$ 70,300,000	30,800,000	20,200,000
Unpaid incentive fee		51,200,000	15,000,000
Executive compensation expense		7,100,000	8,500,000	$ 7,700,000
Unpaid reimbursable compensation		$ 4,900,000	$ 5,000,000
Affirmative vote percentage threshold		66.67%
Termination period notice		180 days
Temination fee period quarters | qtr		8
Termination fee payable		$ 0
Termination period without notice		30 days
S P T Management L L C | Restricted Stock Awards
Related-Party Transactions
Granted (in shares) | shares		1,013,232	341,635	182,861
Grant date values		$ 20,300,000	$ 3,900,000	$ 4,100,000
Share-based expense		$ 9,700,000	$ 3,400,000	$ 4,100,000
S P T Management L L C | Restricted Stock Awards | 2017 Manager Equity Plan
Related-Party Transactions
Award vesting period		3 years