Debt and Financing Lease Obligations - Revolving Credit Facility (Details) - USD ($)	Jun. 05, 2020	May 23, 2018	Apr. 30, 2020	Mar. 18, 2020
Line of Credit Facility [Line Items]
Original principal amount			$ 1,304,690,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum capacity extended under credit facility		$ 650,000,000
Weighted-average interest rate			4.90%
Additional borrowing capacity				$ 275,000,000
Line of Credit [Member] | Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Unused capacity fee percentage		0.25%
Line of Credit [Member] | Revolving Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Unused capacity fee percentage		0.50%
Line of Credit [Member] | Revolving Credit Facility [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Variable basis spread		1.00%
Line of Credit [Member] | Revolving Credit Facility [Member] | Alternate Base Rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Variable basis spread		1.50%
Line of Credit [Member] | Revolving Credit Facility [Member] | Alternate Base Rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Variable basis spread		2.25%
Line of Credit [Member] | Revolving Credit Facility [Member] | Federal Funds Rate [Member]
Line of Credit Facility [Line Items]
Variable basis spread		0.50%
Line of Credit [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Original principal amount			$ 40,000,000.0
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Available borrowing capacity			151,700,000
Sub-facility for letters of credit			2,500,000
Additional borrowing capacity			$ 159,800,000
Revolving Credit Facility [Member] | LIBOR [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Variable basis spread		2.50%
Revolving Credit Facility [Member] | LIBOR [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Variable basis spread		3.25%
Subsequent Event [Member] | Line of Credit [Member] | Revolving Credit Facility [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Variable basis spread	1.00%
Subsequent Event [Member] | Line of Credit [Member] | Revolving Credit Facility [Member] | Alternate Base Rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Variable basis spread	2.00%
Subsequent Event [Member] | Line of Credit [Member] | Revolving Credit Facility [Member] | Alternate Base Rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Variable basis spread	2.75%
Subsequent Event [Member] | Line of Credit [Member] | Revolving Credit Facility [Member] | Federal Funds Rate [Member]
Line of Credit Facility [Line Items]
Variable basis spread	0.50%
Subsequent Event [Member] | Revolving Credit Facility [Member] | LIBOR [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Variable basis spread	3.00%
Subsequent Event [Member] | Revolving Credit Facility [Member] | LIBOR [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Variable basis spread	3.75%