| Leases (Details) $ in Millions | 3 Months Ended | 
|---|---|
| Mar. 31, 2019  USD ($) | |
| Lessee, Lease, Description [Line Items] | |
| Finance lease, renewal term (years) | 5 years | 
| Operating lease not yet commenced, value | $ 33 | 
| Operating lease not yet commenced, term | 11 years | 
| Minimum | |
| Lessee, Lease, Description [Line Items] | |
| Operating lease obligations, term (years) | 1 year | 
| Finance lease obligations, term (years) | 1 year | 
| Maximum | |
| Lessee, Lease, Description [Line Items] | |
| Operating lease obligations, term (years) | 19 years | 
| Finance lease obligations, term (years) | 19 years | 
| Operating lease, renewal term (years) | 5 years | 
| Option to terminate lease, term of option (years) | 1 year | 
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- Definition Lease, Remaining Lease Term No definition available. 
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- Definition Lease, Termination Period No definition available. 
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- Definition Lessee, Operating Lease, Lease Not Yet Commenced, Value No definition available. 
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- Definition Term of lessee's finance lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Term of lessee's finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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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 Term of lessee's operating lease not yet commenced, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Details 
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- Details 
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