Goodwill and Intangible Assets - Goodwill Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2011
Goodwill [Roll Forward]
Beginning balance		$ 167,535	$ 154,112
Acquisitions (Note 3)		23,179	13,423
Goodwill impairment	$ (190,700)	(190,714)		$ (2,080,000)
Ending balance	$ 0	$ 0	$ 167,535

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.

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- 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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