Shareholders' Equity / Partners' Capital - Noncontrolling Interest Activity in Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Class of Stock [Line Items]
Income (loss) allocated to noncontrolling interest	$ (3,150)	$ (30)	$ (2,036)	$ (331)
Consolidated Subsidiaries With Noncontrolling Interest
Class of Stock [Line Items]
Income (loss) allocated to noncontrolling interest	(248)	1	(259)	39
Class A Units
Class of Stock [Line Items]
Income (loss) allocated to noncontrolling interest	$ (2,902)	$ (31)	$ (1,777)	$ (370)

Amount of Net Income (Loss) attributable to noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669625-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
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-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669619-108580

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
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-URI http://asc.fasb.org/extlink&oid=84234705&loc=SL4591551-111686

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