Debt (Schedule of Carrying Values of Debt) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Capital lease obligations		$ 98,600	$ 130,900
Total long-term debt obligations		1,035,800	1,023,200
Less unamortized deferred financing costs	[1]	(9,800)	(12,900)
Total debt, net of deferred financing costs		1,026,000	1,010,300
Current portion of long-term debt		64,600	77,400
Long-term debt		$ 961,379	932,868
Debt [Member] | ASU 2015-03 [Member]
Debt Instrument [Line Items]
Adoption of new accounting pronouncement, reclassification of deferred financing costs from other assets to debt, amount			12,900
Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maturity date		Oct. 29, 2018
Credit Facility [Member] | Revolving Loans [Member]
Debt Instrument [Line Items]
Line of credit facility, maturity date		Oct. 29, 2018
Long-term debt obligations		$ 279,900	208,500
Credit Facility [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, maturity date		Nov. 21, 2019
Long-term debt obligations		$ 237,500	250,000
Senior Notes [Member] | 4.875% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date		Mar. 15, 2023
Long-term debt obligations		$ 400,000	400,000
Other Credit Facilities [Member]
Debt Instrument [Line Items]
Long-term debt obligations		$ 13,400	16,400
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Capital lease obligations, expiration date, range, end		Dec. 01, 2021
Notes Payable [Member]
Debt Instrument [Line Items]
Notes payable, maturity date, range, end		Dec. 15, 2018
Long-term debt obligations		$ 6,400	$ 17,400

[1] The Company adopted ASU 2015-03 as of January 1, 2016, which resulted in the reclassification of $12.9 million of deferred financing costs from other current and other long-term assets to current and long-term debt as of December 31, 2015.