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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of unamortized debt discount (premium) and debt issuance 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

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Long-Term Debt Interest Rates (Details) $ in Thousands, € in Millions		1 Months Ended	2 Months Ended	3 Months Ended			12 Months Ended
	Feb. 01, 2015 USD ($)	Jan. 31, 2015 USD ($)	Feb. 28, 2017 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2017 EUR (€)	Mar. 31, 2015 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 18, 2014	Dec. 08, 2014	Nov. 24, 2014	Dec. 10, 2010	Jan. 20, 2005
Debt Instrument [Line Items]
Repayments of long-term debt							$ 778,209	$ 1,252,302	$ 2,582,901
364 Day Facility
Debt Instrument [Line Items]
Repayments of long-term debt							300,000
Five Year Facility
Debt Instrument [Line Items]
Repayments of long-term debt							950,000
1.875% Senior Notes
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs							$ 3,971	$ 7,823
Debt instrument, interest rate				1.875%	1.875%		1.875%	1.875%		1.875%	1.875%
3.00% Senior Notes
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs							$ 0	$ 1,286
Debt instrument, interest rate				3.00%	3.00%		3.00%	3.00%				3.00%
4.15% Senior Notes
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs							$ 3,372	$ 3,859
Debt instrument, interest rate							4.15%	4.15%				4.15%
4.50% Senior Notes
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs							$ 891	$ 2,380
Debt instrument, interest rate				4.50%	4.50%		4.50%	4.50%					4.50%
5.10% Senior Notes
Debt Instrument [Line Items]
Debt instrument, interest rate														5.10%
Repayments of long-term debt	$ 325,000
5.45% Senior Notes
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs							$ 4,159	$ 4,313
Debt instrument, interest rate							5.45%	5.45%				5.45%
Short-term Debt \| Term Loan
Debt Instrument [Line Items]
Repayments of long-term debt						$ 1,000,000
Weighted-average interest rate						1.67%
Senior Unsecured Cash Bridge Facility \| Bridge Loan
Debt Instrument [Line Items]
Repayments of long-term debt		$ 800,000
Domestic Financial Institution Agreement
Debt Instrument [Line Items]
Long-term line of credit							$ 0	$ 0
Foreign Credit Line U S Dollar Euro Denominated Borrowings
Debt Instrument [Line Items]
Long-term line of credit							0	0
Other Foreign Credit Lines
Debt Instrument [Line Items]
Long-term line of credit							$ 0	$ 0
Senior Notes \| 1.875% Senior Notes
Debt Instrument [Line Items]
Repayments of long-term debt \| €					€ 307.0
Senior Notes \| 3.00% Senior Notes
Debt Instrument [Line Items]
Repayments of long-term debt			$ 250,000
Senior Notes \| 4.50% Senior Notes
Debt Instrument [Line Items]
Repayments of long-term debt				$ 174,700