Summary of Principal Accounting Policies (Details) - USD ($) |
3 Months Ended | 12 Months Ended | |||||
|---|---|---|---|---|---|---|---|
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Accounting Policies [Abstract] | |||||||
| Restricted Cash | [1] | $ 8,000,000 | $ 4,000,000 | ||||
| Restricted cash | 4,000,000 | ||||||
| Impairment losses | 0 | 0 | |||||
| Impairment expense | $ 1,000,000 | $ 129,000,000 | $ 0 | $ 0 | $ 130,000,000 | ||
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill. No definition available.
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| X | ||||||||||
- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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