Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of unrecognized tax benefits
Balance at January 1	$ 8,195	$ 577	$ 4,823
Increase for tax position acquired as result of a business combination	0	0	414
Increases for tax positions taken during the current year	361	7,618	163
(Decreases) for tax positions taken during the current year	0	0	(4,823)
(Decreases) relating to a lapse of the applicable statute of limitations	(203)	0	0
Balance at December 31	$ 8,353	$ 8,195	$ 577

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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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

+ Details

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- Definition

Amount of decrease in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

+ References

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- Definition

Amount of increase in unrecognized tax benefits resulting from acquisitions.

+ References

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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