Debt Instrument, Convertible, Discount Amortization Period

No definition available.

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- Definition

Debt Instrument, Convertible, Maximum Threshold Percentage of Stock Price Trigger

+ References

No definition available.

+ Details

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- Definition

Additional interest rate per year to be payable for any semiannual interest period for which principal amount outstanding on Notes is less than the required amount

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Debt Instrument, Interest Rate Increase, Minimum Principal Amount Outstanding Threshold

+ References

No definition available.

+ Details

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- Definition

The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

+ Details

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Period Type:	duration

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

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

+ Details

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

- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031897-161870

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

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Period Type:	duration

- Definition

Price of the entity's common stock which would be required to be attained for the conversion feature embedded in the debt instrument to become effective.

+ References

No definition available.

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

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- Definition

Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

+ Details

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

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

+ References

+ Details

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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

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

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- Details

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Debt - Convertible Notes (Details) $ / shares in Units, shares in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) d $ / shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Debt Instrument [Line Items]
Net carrying amount of debt	$ 2,041,000,000	$ 2,041,000,000
Loss on debt extinguishment		$ 14,000,000	$ 0	$ 0
1.125% Convertible Notes
Debt Instrument [Line Items]
Percentage of contractual interest rate	1.125%	1.125%
1.625% Convertible Notes
Debt Instrument [Line Items]
Percentage of contractual interest rate	1.625%	1.625%
Convertible Debt \| 1.125% Convertible Notes
Debt Instrument [Line Items]
Net carrying amount of debt	$ 550,000,000	$ 550,000,000
Percentage of contractual interest rate	1.125%	1.125%
Debt instrument conversion price per share (usd per share) \| $ / shares	$ 40.77	$ 40.77
Debt instrument conversion price, trigger price (usd per share) \| $ / shares		$ 53.00
Senior note effective interest rate	6.00%	6.00%
Senior notes amortization period		2 years
If-converted value in excess of principal on convertible debt		$ 406,000,000	182,000,000
Debt instrument, conversion ratio		0.0245277
Convertible Debt \| 1.625% Convertible Notes
Debt Instrument [Line Items]
Net carrying amount of debt	$ 161,000,000	$ 161,000,000
Percentage of contractual interest rate	1.625%	1.625%
Debt instrument conversion price per share (usd per share) \| $ / shares	$ 58.09	$ 58.09
Debt instrument conversion price, trigger price (usd per share) \| $ / shares		$ 75.51
Senior note effective interest rate	5.00%	5.00%
If-converted value in excess of principal on convertible debt		$ 50,000,000
Debt instrument, conversion ratio		0.0172157
Convertible debt, converted amount of instrument	$ 141,000,000
Convertible debt, shares converted in transaction (in shares) \| shares	2.6
Loss on debt extinguishment	$ 14,000,000
Increase of interest rate contingent on principal amount outstanding		0.25%
Minimum principal amount outstanding threshold for interest rate increase	100,000,000	$ 100,000,000
Debt redemption price, percentage of principal amount		100.00%
Term of debt instrument		4 years
Convertible debt discount amortization period		7 months
Convertible debt, carrying amount of equity component	$ 12,000,000	$ 12,000,000	$ 23,000,000
Convertible Debt \| Redemption period, option one \| 1.125% Convertible Notes
Debt Instrument [Line Items]
Debt convertible threshold trading days \| d		20
Debt convertible threshold consecutive trading days \| d		30
Debt convertible threshold percentage of stock price trigger		130.00%
Convertible Debt \| Redemption period, option one \| 1.625% Convertible Notes
Debt Instrument [Line Items]
Debt convertible threshold trading days \| d		20
Debt convertible threshold consecutive trading days \| d		30
Debt convertible threshold percentage of stock price trigger		130.00%
Convertible Debt \| Redemption period, option two \| 1.125% Convertible Notes
Debt Instrument [Line Items]
Debt convertible threshold trading days \| d		5
Debt convertible threshold consecutive trading days \| d		5
Debt convertible maximum threshold percentage of stock price		98.00%
Convertible Debt \| Redemption period, option two \| 1.625% Convertible Notes
Debt Instrument [Line Items]
Debt convertible threshold trading days \| d		5
Debt convertible threshold consecutive trading days \| d		5
Debt convertible maximum threshold percentage of stock price		98.00%