Consolidated Statement of Changes in Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Limited Voting Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Noncontrolling Interests
Balance at Dec. 31, 2013	$ 1,335,521	$ 87	$ 4	$ 1,428,026	$ (2,179)	$ (409,338)	$ 318,921
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	10,966					10,845	121
Change in fair value of interest rate swaps	(121)				(195)	0	74
Common dividends declared-$0.1875 per share	(19,670)					(18,694)	(976)
Share-based compensation	2,489			2,489
Issuance of 11,825,000 shares of common stock, net	205,166	12		205,154
Issuance of 6,834 shares issued pursuant to TPG Management Services Agreement	125			125
Issuance of 85,649 operating partnership units	1,546						1,546
Exercise of Madison Put Option related to merger with Thomas Properties Group, Inc.	(41,539)			(10,522)			(31,017)
Balance at Mar. 31, 2014	$ 1,494,483	$ 99	$ 4	$ 1,625,272	$ (2,374)	$ (417,187)	$ 288,669