Investment in Joint Venture Arrangements Investment in Joint Venture Arrangements Balance Sheet Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Single-family lots, land and land development costs (a) (b)	$ 13,289	$ 30,794
Other assets	5,143	1,040
Total assets	18,432	31,834
Notes payable	261	1,287
Other liabilities	1,544	2,723
Total liabilities	1,805	4,010
Company’s equity (a) (b)	8,328	16,015
Other equity	8,299	11,809
Total partners’ equity	16,627	27,824
Total liabilities and partners’ equity	18,432	31,834
Reduction of impairment relating to joint venture arrangements	1,733	536
Company's investment in joint development or similar agreements	$ 13,930	$ 12,537