Related-Party Transactions - Management Agreement (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) qtr d shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares
Related-Party Transactions
Trading days period | d	5
Granted (in shares) | shares	914,694
Share-based expense	$ 52,949,000	$ 65,089,000	$ 74,421,000
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	$ 87,300,000	86,700,000	77,900,000
Base management fee payable	$ 21,900,000	21,800,000
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%
Incentive fee quarters period | qtr	3
Percentage of installment payable in shares	50.00%
Stock ownership limit	9.80%
Accrued incentive fee	$ 35,700,000	49,600,000	70,300,000
Unpaid incentive fee	19,500,000	14,500,000
Executive compensation expense	8,000,000	8,600,000	$ 7,100,000
Unpaid reimbursable compensation	$ 3,400,000	$ 4,900,000
Percentage of votes needed to terminate agreement	66.67%
Termination period notice	180 days
Termination fee multiplier	3
Termination 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	226,955	200,972	1,013,232
Grant date values	$ 4,300,000	$ 4,800,000	$ 20,300,000
Share-based expense	$ 8,700,000	$ 8,900,000	$ 9,700,000
S P T Management L L C | Restricted Stock Awards | Manager Equity Plan
Related-Party Transactions
Vesting Period	3 years
S P T Management L L C | Employee Stock
Related-Party Transactions
Share-based expense	$ 0