Borrowings Under Credit Facilities and Commercial Paper Program - Aggregate Borrowings Under Unsecured Revolving Credit Facility and Commercial Paper (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Debt Disclosure [Abstract]
Balance outstanding at quarter end	$ 655,000	$ 291,000	$ 655,000	$ 291,000
Maximum amount outstanding at any month end	1,565,000	990,000	1,565,000	990,000
Average amount outstanding (total of daily principal balances divided by days in period)	$ 1,047,631	$ 470,935	$ 937,045	$ 255,114
Weighted average interest rate (actual interest expense divided by average borrowings outstanding)	2.76%	0.21%	1.58%	0.42%