Goodwill and Other Intangible Assets - Schedule of changes in the carrying amount of goodwill (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Goodwill | |||||||||||
| Beginning balance | $ 306,691 | $ 303,875 | $ 306,691 | $ 303,875 | |||||||
| Goodwill resulting from business combination and purchase price adjustments | 2,816 | ||||||||||
| Goodwill impairment | $ 0 | $ 0 | $ (131,997) | $ 0 | $ 0 | $ 0 | $ 0 | $ 0 | (131,997) | 0 | $ 0 |
| Goodwill related to disposed assets | (103,474) | (103,474) | |||||||||
| Effect of currency translation adjustment | 23 | ||||||||||
| Ending balance | $ 71,243 | $ 306,691 | $ 71,243 | $ 306,691 | $ 303,875 | ||||||
| X | ||||||||||
- Definition Amount classified as goodwill attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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| X | ||||||||||
- Definition Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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