Segment Information (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Financial data of five reportable segments
Total Assets	$ 8,551,521,000		$ 8,551,521,000		$ 8,952,025,000
Revenues	229,637,000	277,915,000	479,174,000	547,881,000
Operating Expenses	145,807,000	187,006,000	316,910,000	371,273,000
Depreciation and amortization	59,318,000	80,452,000	114,327,000	148,256,000
Interest expense	57,153,000	83,096,000	119,605,000	164,579,000
Interest and other income	12,375,000	11,775,000	23,878,000	22,425,000
Capital expenditures	121,069,000	125,272,000	231,810,000	240,518,000
Commercial Group [Member]
Financial data of five reportable segments
Total Assets	4,300,903,000		4,300,903,000		5,120,360,000
Revenues	123,791,000	177,921,000	253,876,000	350,802,000
Operating Expenses	73,157,000	97,746,000	154,705,000	197,327,000
Depreciation and amortization	32,193,000	58,102,000	62,452,000	99,787,000
Interest expense	32,279,000	49,216,000	66,845,000	99,428,000
Interest and other income	2,222,000	2,146,000	4,006,000	4,070,000
Capital expenditures	49,381,000	49,752,000	80,378,000	108,624,000
Residential Group [Member]
Financial data of five reportable segments
Total Assets	2,727,891,000		2,727,891,000		2,468,708,000
Revenues	61,553,000	63,950,000	127,222,000	127,281,000
Operating Expenses	37,673,000	47,497,000	83,342,000	95,024,000
Depreciation and amortization	17,656,000	13,490,000	33,052,000	30,021,000
Interest expense	5,817,000	10,109,000	15,002,000	16,716,000
Interest and other income	6,599,000	6,307,000	13,044,000	12,261,000
Capital expenditures	71,058,000	57,276,000	144,849,000	97,700,000
Arena [Member]
Financial data of five reportable segments
Total Assets	965,774,000		965,774,000		984,937,000
Revenues	24,572,000	26,853,000	59,929,000	50,993,000
Operating Expenses	14,818,000	21,898,000	38,294,000	40,310,000
Depreciation and amortization	8,674,000	8,001,000	17,206,000	16,374,000
Interest expense	9,649,000	9,393,000	19,206,000	18,275,000
Interest and other income	0	0	0	0
Capital expenditures	615,000	17,893,000	6,552,000	32,913,000
Land Development Group [Member]
Financial data of five reportable segments
Total Assets	285,587,000		285,587,000		260,070,000
Revenues	19,721,000	9,191,000	38,147,000	18,805,000
Operating Expenses	10,100,000	6,387,000	18,949,000	14,075,000
Depreciation and amortization	95,000	103,000	181,000	429,000
Interest expense	(147,000)	(167,000)	(285,000)	(438,000)
Interest and other income	3,462,000	3,210,000	6,707,000	5,932,000
Capital expenditures	0	122,000	16,000	829,000
Corporate Activities [Member]
Financial data of five reportable segments
Total Assets	271,366,000		271,366,000		117,950,000
Revenues	0	0	0	0
Operating Expenses	10,059,000	13,478,000	21,620,000	24,537,000
Depreciation and amortization	700,000	756,000	1,436,000	1,645,000
Interest expense	9,555,000	14,545,000	18,837,000	30,598,000
Interest and other income	92,000	112,000	121,000	162,000
Capital expenditures	$ 15,000	$ 229,000	$ 15,000	$ 452,000