Debt and Lease Obligations (Maturities of Debt by Type) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 60,000	$ 60,000	$ 45,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	75,599
2018	66,066
2019	44,947
2020	0
2021	1,091,235
Thereafter	297,410
Total	1,575,257
Term Loan
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	60,000
2018	59,468
2019	44,947
2020	0
2021	0
Thereafter	0
Total	164,415
Senior Notes and other debt
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	15,599
2018	6,598
2019	0
2020	0
2021	1,091,235
Thereafter	297,410
Total	1,410,842
Term Loan
Debt Instrument [Line Items]
Repayments of Long-term Debt	60,000	60,000	$ 45,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Total	$ 164,415	$ 224,255