Debt Obligations - Borrowings and Repayments (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 17, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Borrowings
Borrowings from revolving line of credit		$ 204,400	$ 24,000	$ 107,900
Total		304,400	24,000	207,900
Repayments
Bank borrowings		(183,400)	(28,000)	(126,000)
Senior unsecured notes		(47,160)	(40,160)	(33,667)
Total		(230,560)	(68,160)	(159,667)
Term loans, net of debt issue cost		722,719	649,382
Available for borrowing		289,100	510,100
Bank Borrowings
Borrowings
Total		204,400	24,000	107,900
Repayments
Total		(183,400)	(28,000)	(126,000)
Term loans, net of debt issue cost		110,900	89,900
Available for borrowing		289,100	510,100
Term loans
Borrowings
Total		100,000
Repayments
Term loans, net of debt issue cost		99,363
Senior Unsecured Notes
Borrowings
Total				100,000
Repayments
Total	$ (7,000)	(47,160)	(40,160)	(33,667)
Term loans, net of debt issue cost	$ 505,456	$ 512,456	$ 559,482
Senior Unsecured Notes | Private Shelf Agreement Prudential
Repayments
Face amount of debt				$ 100,000
Fixed interest rate (as a percent)				3.85%