Basis of Presentation and Significant Accounting Policies - Additional Information (Details) - USD ($)		6 Months Ended
	Jan. 01, 2018	Jun. 30, 2018	Jun. 30, 2017
Property Plant And Equipment [Line Items]
Decrease in cash provided by used in operating activities continuing operations		$ 106,511,000	$ 78,992,000
Increase in cash provided by used in investing activities continuing operations		(80,960,000)	492,123,000
Adjustment to investments in unconsolidated joint ventures		$ 7,086,000
ASU 2016-18 [Member]
Property Plant And Equipment [Line Items]
Decrease in cash provided by used in operating activities continuing operations			(3,000,000)
Increase in cash provided by used in investing activities continuing operations			$ 16,010,000
ASU 2017-05 [Member] | RDF [Member] | One Steuart Lane [Member]
Property Plant And Equipment [Line Items]
Adjustment to investments in unconsolidated joint ventures	$ 7,086,000