Valuation Adjustments and Write-offs Valuation Adjustments and Write-offs (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Impairment of investments in Unconsolidated LLCs	$ 0		$ 390
Total valuation adjustments and write-offs	900	126
Impairment of Operating Communities [Member]
Impairment of operating communities	0	0
Impairment of Future Communities [Member]
Impairment of future communities	252	0
Impairment of Land Held for Sale [Member]
Impairment of land held for sale	648	95
Option Deposits and Pre-Acquisition Write-Offs [Member]
Option deposits and pre-acquisition costs write-offs	0	31
Impairment of Investments in Unconsolidated LLCs [Member]
Impairment of investments in Unconsolidated LLCs	0	0
Midwest Homebuilding [Member] | Impairment of Operating Communities [Member]
Impairment of operating communities	0	0
Midwest Homebuilding [Member] | Impairment of Future Communities [Member]
Impairment of future communities	252	0
Midwest Homebuilding [Member] | Impairment of Land Held for Sale [Member]
Impairment of land held for sale	648	95
Midwest Homebuilding [Member] | Option Deposits and Pre-Acquisition Write-Offs [Member]
Option deposits and pre-acquisition costs write-offs	0	2
Midwest Homebuilding [Member] | Impairment of Investments in Unconsolidated LLCs [Member]
Impairment of investments in Unconsolidated LLCs	0	0
Southern Homebuilding [Member] | Impairment of Operating Communities [Member]
Impairment of operating communities	0	0
Southern Homebuilding [Member] | Impairment of Future Communities [Member]
Impairment of future communities	0	0
Southern Homebuilding [Member] | Impairment of Land Held for Sale [Member]
Impairment of land held for sale	0	0
Southern Homebuilding [Member] | Option Deposits and Pre-Acquisition Write-Offs [Member]
Option deposits and pre-acquisition costs write-offs	0	7
Southern Homebuilding [Member] | Impairment of Investments in Unconsolidated LLCs [Member]
Impairment of investments in Unconsolidated LLCs	0	0
Mid-Atlantic Homebuilding [Member] | Impairment of Operating Communities [Member]
Impairment of operating communities	0	0
Mid-Atlantic Homebuilding [Member] | Impairment of Future Communities [Member]
Impairment of future communities	0	0
Mid-Atlantic Homebuilding [Member] | Impairment of Land Held for Sale [Member]
Impairment of land held for sale	0	0
Mid-Atlantic Homebuilding [Member] | Option Deposits and Pre-Acquisition Write-Offs [Member]
Option deposits and pre-acquisition costs write-offs	0	22
Mid-Atlantic Homebuilding [Member] | Impairment of Investments in Unconsolidated LLCs [Member]
Impairment of investments in Unconsolidated LLCs	$ 0	$ 0