Long-term Debt Long Term Debt (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Less: unamortized debt issuance costs long-term	$ (25,175)	$ (33,186)
Long-term debt	2,331,295	2,359,453
Less: current portion, net of unamortized debt issuance costs	27,853	52,538
Long-term debt, less current portion	2,303,442	2,306,915
Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 1,567,882	$ 1,630,406
Debt Instrument, Interest Rate, Stated Percentage	2.82%	2.71%
Debt Instrument, Maturity date	Mar. 31, 2020
Australia Credit Agreement
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 525,101	$ 498,801
Debt Instrument, Interest Rate, Stated Percentage	4.28%	4.64%
Debt Instrument, Maturity date	Dec. 01, 2021
Partner Loan Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 186,085	$ 172,154
Debt Instrument, Interest Rate, Stated Percentage	6.50%	6.51%
Debt Instrument, Maturity date	Nov. 01, 2026
Other debt and capital leases [Member]
Debt Instrument [Line Items]
Other debt and capital leases	$ 77,402	$ 91,278

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13,16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

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