Fair Values of Financial and Nonfinancial Instruments (Details 3) (USD $)	6 Months Ended			12 Months Ended	6 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Level 3 Other assets held-for-sale	Dec. 31, 2011 Level 3 Other assets held-for-sale	Jun. 30, 2012 Level 3 Investments in joint ventures	Dec. 31, 2011 Level 3 Investments in joint ventures	Jun. 30, 2012 Measured on a non-recurring basis Level 3	Dec. 31, 2011 Measured on a non-recurring basis Level 3	Jun. 30, 2012 Measured on a non-recurring basis Level 3 Housing inventory and inventory held-for-sale	Dec. 31, 2011 Measured on a non-recurring basis Level 3 Housing inventory and inventory held-for-sale	Jun. 30, 2012 Measured on a non-recurring basis Level 3 Other assets held-for-sale and investments in joint ventures	Dec. 31, 2011 Measured on a non-recurring basis Level 3 Other assets held-for-sale and investments in joint ventures
Nonfinancial instruments measured on nonrecurring basis
Impairment charges	$ 2,454,000	$ 14,922,000	$ 0	$ 35,000	$ 20,000	$ 2,000,000			$ 1,900,000	$ 9,500,000
Fair value of impaired assets			$ 0	$ 973,000	$ 1,300,000	$ 1,400,000	$ 3,374,000	$ 11,487,000	$ 2,074,000	$ 9,121,000	$ 1,300,000	$ 2,366,000