Noncontrolling Interest - Summary of Activity for Equity Attributable to Noncontrolling Interest (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
December 31, 2017	$ 446,558
Net loss attributable to noncontrolling interest	52,888	$ (32,219)
December 31, 2018	491,852	446,558
Bold Transaction
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
December 31, 2017	446,558
Noncontrolling interest recorded within equity in connection with the closing of the Bold Transaction	(7,594)
Net loss attributable to noncontrolling interest	52,888
December 31, 2018	$ 491,852	$ 446,558

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(24))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(22))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant