Fair Value Measurement (Carrying Values and Fair Values of the Company's Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021	Feb. 08, 2021	Dec. 31, 2020
5.00% Notes due April 2024 | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	5.00%	5.00%	5.00%
4.75% Notes due August 2025 | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	4.75%
4.25% Notes due February 2029 | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	4.25%		4.25%
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	$ 2,838,062			$ 2,849,307
Carrying Amount | Term Loan A Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	663,912			669,878
Carrying Amount | 5.00% Notes due April 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	397,448			991,074
Carrying Amount | 4.75% Notes due August 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	791,597			790,125
Carrying Amount | 4.25% Notes due February 2029
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	983,605
Carrying Amount | 4.75% Notes due December 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt				398,230
Carrying Amount | Other debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	1,500
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	2,889,238			2,907,379
Estimated Fair Value | Term Loan A Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	669,938			665,719
Estimated Fair Value | 5.00% Notes due April 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	406,000			1,015,000
Estimated Fair Value | 4.75% Notes due August 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	820,000			826,160
Estimated Fair Value | 4.25% Notes due February 2029
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	991,800
Estimated Fair Value | 4.75% Notes due December 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt				$ 400,500
Estimated Fair Value | Other debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt	$ 1,500