Business Segments Business Segments - Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Deposits on real estate under option or contract	$ 32,122	$ 32,556
Inventory	1,719,403	1,382,018
Investment in joint venture arrangements	24,568	20,525
Other assets	282,242	429,672
Total assets	2,058,335	1,864,771
Midwest Homebuilding [Member]
Segment Reporting Information [Line Items]
Deposits on real estate under option or contract	5,480	4,933
Inventory	716,502	500,671
Investment in joint venture arrangements	534	4,410
Other assets	27,820	13,573
Total assets	750,336	523,587
Southern Homebuilding [Member]
Segment Reporting Information [Line Items]
Deposits on real estate under option or contract	20,194	20,719
Inventory	736,966	636,019
Investment in joint venture arrangements	5,342	9,677
Other assets	46,036	38,784
Total assets	808,538	705,199
Mid-Atlantic Homebuilding [Member]
Segment Reporting Information [Line Items]
Deposits on real estate under option or contract	6,448	6,904
Inventory	265,935	245,328
Investment in joint venture arrangements	18,692	6,438
Other assets	8,331	13,311
Total assets	299,406	271,981
Corporate, Financial Services and Unallocated [Member]
Segment Reporting Information [Line Items]
Deposits on real estate under option or contract	0	0
Inventory	0	0
Investment in joint venture arrangements	0	0
Other assets	200,055	364,004
Total assets	$ 200,055	$ 364,004