Consolidation of Joint Ventures and Long-Term Debt Joint Venture - Additional Information (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 143,312,000	$ 102,254,000
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ 66,018,000	$ 53,278,000

The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5710-111685

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