v3.8.0.1

Debt - Interest Rate Swaps (Details) - USD ($)	Dec. 31, 2017	Feb. 28, 2017	Nov. 30, 2016	Feb. 29, 2016
February 15, 2021
Debt Instrument [Line Items]
Derivative, notional amount	$ 600,000,000			$ 600,000,000
Swap average, variable interest rate				4.22%
May 15, 2022
Debt Instrument [Line Items]
Derivative, notional amount	500,000,000
February 15, 2024
Debt Instrument [Line Items]
Derivative, notional amount	1,000,000,000			$ 1,000,000,000
Swap average, variable interest rate				4.44%
January 15, 2025
Debt Instrument [Line Items]
Derivative, notional amount	600,000,000	$ 600,000,000
Derivative, interest rate		2.53%
Interest rate swap
Debt Instrument [Line Items]
Derivative, notional amount	$ 2,700,000,000
Swap average, variable interest rate	3.61%
Weighted average interest rate, interest rate swap agreements	4.99%
$1,200 million 4.75% Senior notes, due January 15, 2025 | Senior Notes
Debt Instrument [Line Items]
Face amount	$ 1,200,000,000		$ 1,200,000,000
Interest rate stated, percentage	4.75%		4.75%
Five Point Seven Five Percent Senior Notes, Due June first twenty seventeen | Senior Notes
Debt Instrument [Line Items]
Face amount			$ 425,000,000
Interest rate stated, percentage			5.75%
Five Point Seven Five Percent Senior Notes, Due June first twenty seventeen | Senior Notes | Interest rate swap
Debt Instrument [Line Items]
Derivative, notional amount			$ 250,000,000

X

- Definition

weighted average interest rate, interest rate swap agreements

+ References

No definition available.

+ Details

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X

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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Balance Type:	credit
Period Type:	instant

X

- 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.

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X

- Definition

The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Variable interest rate in effect as of the balance sheet date related to the interest rate derivative.

+ References

No definition available.

+ Details

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