Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
OPERATING ACTIVITIES
Net income	$ 19,324	$ 2,174	$ 5,239
Results from discontinued operations	(5,080)	(331)	(494)
Income from continuing operations	14,244	1,843	4,745
Adjustments to reconcile income from continuing operations to net cash provided by operating activities:
Deferred rent revenue and amortization of lease intangibles	(2,616)	2,124	623
Depreciation and amortization	57,639	36,356	28,473
Amortization of debt issuance costs and debt fair value adjustments	3,954	561	614
Early extinguishment of debt	25,867
Loan transfer and consent fees	9,019
Gain on acquisition of controlling interests	(46,371)	(4,297)
Stock-based compensation expense	2,615
Loss from real estate joint ventures	188	4,406	4,865
Distribution of earnings from real estate joint ventures		6,714	7,634
Other, net	2,669	794	267
Changes in operating assets and liabilities
Change in restricted cash	112	(27)	(55)
Change in accounts receivable	(3,566)	87	91
Change in prepaid expenses and other assets	(2,037)	(5,135)	(89)
Change in accounts payable and accrued expenses	2,526	3,342	(1,411)
Change in security deposits and other liabilities	(616)	60	(13)
Net cash provided by operating activities of continuing operations	63,627	46,828	45,744
Net cash provided by operating activities of discontinued operations	1,737	1,518	1,757
Net cash provided by operating activities	65,364	48,346	47,501
INVESTING ACTIVITIES
Acquisition of real estate, net of cash acquired	(228,558)	(32,962)
Capital expenditures	(10,956)	(4,122)	(6,291)
Change in restricted cash	(3,070)		(17)
Cash acquired from acquisition of controlling interests in real estate joint ventures	15,222
Leasing commissions	(3,295)	(1,635)	(1,551)
Purchase of marketable securities	(33,103)
Maturity of marketable securities	4,993
Deposit on property acquisition	(3,000)
Distribution of capital from real estate joint ventures		10,607
Issuance of notes receivable to affiliate		(800)	(30)
Repayment of notes receivable from affiliates			1,160
Net cash used in investing activities of continuing operations	(261,767)	(28,912)	(6,729)
Net cash provided by (used in) investing activities of discontinued operations	30,078	(593)	(815)
Net cash used in investing activities	(231,689)	(29,505)	(7,544)
FINANCING ACTIVITIES
Issuance of secured notes payable	84,500	7,500	24,887
Repayment of secured notes payable	(264,250)	(12,873)	(25,172)
Defeasance costs on repayment of secured notes payable	(24,345)
Loan transfer and consent fees paid	(8,350)
Issuance of unsecured notes payable		36,200
Repayment of unsecured notes payable	(38,013)	(11,051)	(8,279)
Repayment of notes payable to affiliates	(19,279)	(2,401)	(2,173)
Debt issuance costs	(2,961)	(436)	(559)
Proceeds from issuance of common stock, net	596,541
Proceeds from private placement of common units	5,410
Dividends paid to common stock and unitholders	(46,123)
Payments to nonaccredited investors	(6,075)
Contributions from Predecessor's controlling and noncontrolling interests		7,665	1,196
Distributions to Predecessor's controlling and noncontrolling interests	(39,960)	(25,681)	(24,646)
Net cash provided by (used in) financing activities	237,095	(1,077)	(34,746)
Net increase in cash and cash equivalents	70,770	17,764	5,211
Cash and cash equivalents, beginning of period	41,953	24,189	18,978
Cash and cash equivalents, end of period	$ 112,723	$ 41,953	$ 24,189