Fair Value Measurement (Carrying Values And Fair Values Of The Company's Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	$ 3,109,555	$ 3,099,257
Long-term Debt, Fair Value	2,989,334	3,166,375
Term-A Facility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	739,710	737,140
Long-term Debt, Fair Value	738,750	748,125
4.75% Senior Notes Due 2025 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	786,458	784,757
Long-term Debt, Fair Value	720,000	793,000
5.00% Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	986,275	984,056
Long-term Debt, Fair Value	947,500	1,012,500
4.75% Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	594,528	593,304
Long-term Debt, Fair Value	580,500	$ 612,750
Other Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	2,584
Long-term Debt, Fair Value	$ 2,584