Net Gain (Loss) on Disposition of Partial Interests in Rental Properties (Details) (USD $)	11 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Net gain on disposition of partial interests in rental properties
Net gain on disposition of partial interests in rental properties	$ 496,092,000	$ 0	$ 0	$ 17,665,000
QIC Joint Venture [Member]
Net gain on disposition of partial interests in rental properties
Net gain on disposition of partial interests in rental properties	381,627,000		0	0
New York Retail Joint Venture [Member]
Net gain on disposition of partial interests in rental properties
Net gain on disposition of partial interests in rental properties	114,465,000		0	9,561,000
Stonecrest Mall Joint Venture [Member]
Net gain on disposition of partial interests in rental properties
Net gain on disposition of partial interests in rental properties	0		0	5,849,000
Annex building adjacent to the Dallas Wilson Building [Member]
Net gain on disposition of partial interests in rental properties
Net gain on disposition of partial interests in rental properties	$ 0		$ 0	$ 2,255,000