Derivative Instruments - Schedule of Notional Amounts of Outstanding Derivative Positions (Details) - CCH Interest Rate Derivatives [Member] $ in Millions  | 
12 Months Ended | 
|---|---|
| 
 Dec. 31, 2018  
USD ($) 
 | |
| Derivative [Line Items] | |
| Initial Notional Amount | $ 29 | 
| Effective Date | May 20, 2015 | 
| Maturity Date | May 31, 2022 | 
| Weighted Average Fixed Interest Rate Paid | 2.30% | 
| Variable Interest Rate Received | One-month LIBOR | 
| Maximum [Member] | |
| Derivative [Line Items] | |
| Initial Notional Amount | $ 4,700 | 
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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition When the derivative or group of derivatives presented is a swap, the type of interest rate (fixed, variable, stepped, etc.) paid on the swap. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Average fixed interest rate related to the group of interest rate derivatives. No definition available. 
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- Definition Date the entity entered into the derivative contract, in CCYY-MM-DD format. No definition available. 
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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. No definition available. 
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- Definition Date the derivative contract matures, in CCYY-MM-DD format. No definition available. 
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- Details 
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- Details 
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