Non-controlling Interests Non-controlling Interests (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Noncontrolling Interests [Abstract]
Net income attributable to common shareholders	$ 115,599		$ 40,036
Increase in equity for conversion of operating partnership units	16		0
Decrease in additional paid-in capital for purchase of remaining non-controlling ownership interests in two consolidated joint ventures (1)	(9,480)	[1]	0	[1]
Change in common shareholders' equity and net transfers from noncontrolling interests	$ 106,135		$ 40,036

[1] Refer to Note 5, "Acquisitions and Dispositions," for further discussion of acquisitions.