Basis of Presentation and Significant Accounting Policies - Narrative (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($) land_parcel	Jun. 30, 2019 USD ($) land_parcel segment	Jun. 30, 2018 USD ($) land_parcel	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Number of land parcels sold | land_parcel		2	3	3
Operating revenue	$ 465,469,000	$ 519,452,000	$ 921,333,000	$ 892,820,000
Number of reportable segments | segment			7
Minimum
Significant Accounting Policies [Line Items]
Percentage of sales price fee from construction management agreements					300.00%
Maximum
Significant Accounting Policies [Line Items]
Percentage of sales price fee from construction management agreements					5.00%
Land
Significant Accounting Policies [Line Items]
Operating revenue	$ 1,900,000