Debt (Textual) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 23, 2020
Debt Instrument [Line Items]
Maximum amount borrowed	$ 1,157,200,000
Loss due to debt prepayment, reclassified into earnings	2,800,000
Write off of debt issuance cost	300,000
Interest paid	51,600,000	$ 59,600,000	$ 29,600,000
Unused capacity	$ 728,600,000
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.66%	3.24%
Estimated fair value
Debt Instrument [Line Items]
Fair value of long-term debt	$ 1,026,800,000	$ 1,096,000,000.0
Recourse
Debt Instrument [Line Items]
Aggregate annual maturities of long term debt, 2019	69,000,000.0
Aggregate annual maturities of long term debt, 2020	57,000,000.0
Aggregate annual maturities of long term debt, 2021	65,200,000
Aggregate annual maturities of long term debt, 2022	143,600,000
Aggregate annual maturities of long term debt, 2023	44,600,000
Aggregate annual maturities of long term debt thereafter	468,200,000
Non-recourse
Debt Instrument [Line Items]
Aggregate annual maturities of long term debt, 2019	6,400,000
Aggregate annual maturities of long term debt, 2020	15,500,000
Aggregate annual maturities of long term debt, 2021	11,600,000
Aggregate annual maturities of long term debt, 2022	74,900,000
Aggregate annual maturities of long term debt, 2023	10,500,000
Aggregate annual maturities of long term debt thereafter	$ 32,500,000
Loans Payable [Member]
Debt Instrument [Line Items]
Face amount				$ 150,000,000.0