Borrowings - Short-Term Credit Facilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Weighted Average Interest Rate	2.40%	4.50%
Borrowing Outstanding	$ 1,670,410
Interest expense	$ 87,735	$ 121,859	$ 71,800
Short-Term Credit Facilities
Short-term Debt [Line Items]
Weighted Average Interest Rate	2.77%	4.22%
Financing Available	$ 616,000	$ 586,000
Borrowing Outstanding	134,664	134,331
Interest expense	$ 4,800	$ 6,600	$ 7,100