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Long-Term Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Nov. 03, 2016	Aug. 31, 2013
Debt Instrument [Line Items]
Capital Leases	$ 886	$ 2,324
Total	1,920,633	1,870,528
Less - current portion	49,557	47,225
Long-term portion	1,871,076	1,823,303
Revolving Credit Facility
Debt Instrument [Line Items]
Unamortized discount and debt issuance cost	2,122	2,451
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	900,509	853,124
Other Borrowings
Debt Instrument [Line Items]
Long-term debt	10,565	6,860
Senior Notes Due 2026
Debt Instrument [Line Items]
Long-term debt	$ 747,721	747,655
Stated interest rate (as a percent)	3.45%
Unamortized discount and debt issuance cost	$ 2,279	2,345
Senior Notes Due 2026 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt	747,721	747,655
Stated interest rate (as a percent)			3.45%
4.375% Senior Notes, due 2023
Debt Instrument [Line Items]
Long-term debt	$ 248,631	248,567
Stated interest rate (as a percent)	4.375%
Unamortized discount and debt issuance cost	$ 1,369	1,433
4.375% Senior Notes, due 2023 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt	248,631	248,567
Stated interest rate (as a percent)				4.375%
Schuldschein Loan
Debt Instrument [Line Items]
Long-term debt	$ 12,321	$ 11,998