Revolving Credit Facility (Details) - Credit And Guarantee Agreement - Line of Credit - USD ($)		1 Months Ended
	Apr. 30, 2017	Apr. 30, 2019	Jun. 30, 2020	Feb. 28, 2018
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 600,000,000.0			$ 725,000,000.0
Debt issuance fees	$ 2,600,000			400,000
Debt instrument, term		5 years
Line of credit facility, accordion feature, increase limit				275,000,000.0
Unused capacity, commitment fee (percent)	0.20%
Covenant terms, minimum liquidity balance	$ 100,000,000.0
Aggregate letters of credit outstanding amount			$ 45,600,000
Remaining borrowing capacity			$ 679,400,000
Revolving Credit Facility | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)	1.50%
Revolving Credit Facility | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)	0.50%
Letter of Credit
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity				$ 187,500,000
Commitment fee (percent)	1.50%
Fronting fee (percent)	0.125%