Income Taxes - Uncertain Tax Benefits (Details) - USD ($) $ in Thousands		12 Months Ended
May 17, 2017	Dec. 31, 2018	Dec. 31, 2017
Uncertain Tax Benefits
Balance, beginning		$ 812
Additions for the current year tax			$ 812
Additions related to prior years		4
Balance, Ending		816	812
Payables related to Tax Receivable Agreement		56,149	24,675
Tax Receivable Agreement
Uncertain Tax Benefits
Payables related to Tax Receivable Agreement		$ 56,149	$ 24,675
Payments of net cash saving (as a percent)	85.00%	85.00%

Represents the percentage of payments of net cash saving in taxes that the entity realizes that are payable.

No definition available.

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- Definition

The amount for notes payable (written promise to pay), payable to related parties, which are due after one year (or one business cycle).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
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-Section S99
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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.

+ Details

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 10B
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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
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