Recent Accounting Developments - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
	Jan. 01, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 1,418,617		$ 1,524,878
Long-term debt and finance leases, less current maturities		3,048,378		$ 3,066,635
Provision (benefit) for income taxes		$ (25,860)	$ (46,766)
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2020-06
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					$ 6,100
Long-term debt and finance leases, less current maturities	$ 75,600
Provision (benefit) for income taxes	17,100
Debt Issuance Costs, Gross	$ 2,900