Debt (Details)	9 Months Ended
Sep. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)
Debt Instrument [Line Items]
Fair value	$ 1,689,000,000	$ 1,125,800,000
Debt and Capital Lease Obligations	1,528,000,000	952,800,000
Face amount of note convertible into common shares	1,000
Convertible Senior Notes Due 2018
Debt Instrument [Line Items]
Debt	550,000,000	550,000,000
Fair value	665,100,000	709,500,000
Debt and Capital Lease Obligations	$ 547,300,000	546,000,000
Debt Instrument, Interest Rate, Stated Percentage	3.75%
Number of common shares into which notes are convertible (in shares per one thousand dollar note)	64.3407
Senior Notes Due 2024
Debt Instrument [Line Items]
Debt	$ 400,000,000	400,000,000
Fair value	432,500,000	404,600,000
Debt and Capital Lease Obligations	$ 395,500,000	395,100,000
Debt Instrument, Interest Rate, Stated Percentage	4.875%
Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt	$ 550,000,000
Fair value	550,600,000	0
Debt and Capital Lease Obligations	$ 544,400,000	0
Debt Instrument, Interest Rate, Stated Percentage	3.875%
ESSOP Debt
Debt Instrument [Line Items]
Fair value	$ 8,100,000	11,700,000
Debt and Capital Lease Obligations	$ 8,100,000	$ 11,700,000
Debt, Weighted Average Interest Rate	3.95%	3.69%
Debt [Member]
Debt Instrument [Line Items]
Fair value	$ 32,500,000	$ 0
Debt and Capital Lease Obligations	$ 32,400,000	$ 0
Debt, Weighted Average Interest Rate	1.80%

The face amount of an individual note that is convertible into a specified number of shares of common stock.

No definition available.

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- Definition

The number of equity instruments that the holder of the debt instrument would receive if the debt was converted to equity.

+ References

No definition available.

+ Details

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- Definition

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.

+ References

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

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-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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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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-Topic 835
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-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13433-108611

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-Paragraph 12
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- Definition

Contractual interest rate for funds borrowed, under the debt 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(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- 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

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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