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Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Parenthetical) (Details) | 6 Months Ended
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Jun. 30, 2018 USD ($)
Derivative [Line Items] |
Debt instrument, maturity date | Jan. 10, 2022
Forward Starting Swaps [Member] |
Derivative [Line Items] |
Current Notional Balance | $ 800,000,000
Forward Starting Swaps Mandatory Counterparty Terminations in 2019 [Member] |
Derivative [Line Items] |
Current Notional Balance | 300,000,000
Forward Starting Swaps Mandatory Counterparty Terminations in 2020 [Member] |
Derivative [Line Items] |
Current Notional Balance | 500,000,000
2.375% Notes [Member] |
Derivative [Line Items] |
Proceeds from issuance of unsecured debt | $ 450,000,000
Debt instrument, interest rate, stated percentage | 2.375%
Debt instrument, maturity date | Jul. 01, 2019
2.375% Notes [Member] | London Interbank Offered Rate (LIBOR) [Member] |
Derivative [Line Items] |
Debt instrument, basis spread on variable rate | 0.61%
Debt instrument, description of variable rate basis | 90-Day LIBOR

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- 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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- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
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- Definition The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. + References No definition available. + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
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- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
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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 The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585 + Details
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