Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 101,932	$ 2,388
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):
Depreciation and amortization of building and improvements and leasing costs	48,717	50,011
Increase in provision for bad debts	0	95
Depreciation of furniture, fixtures and equipment	485	380
Noncash amortization of share-based compensation awards	2,502	2,234
Noncash amortization of deferred financing costs and debt discounts and premiums	1,256	1,413
Noncash amortization of net below market rents (Note 3)	(1,734)	(2,047)
Net gain on dispositions of discontinued operations (Note 13)	(90,115)	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	(2,353)	(2,442)
Straight-line rents	(3,959)	(6,724)
Net change in other operating assets	(5,949)	(7,390)
Net change in other operating liabilities	(5,701)	18,581
Net cash provided by operating activities	45,081	56,499
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisition of operating properties (Note 2)	(106,125)	(85,692)
Expenditures for operating properties	32,016	25,571
Expenditures for development and redevelopment properties and undeveloped land	(73,626)	(73,369)
Net proceeds received from dispositions of operating properties (Note 13)	309,824	0
(Increase) decrease in restricted cash (Notes 1 and 13)	(779)	228,079
Net cash provided by investing activities	97,278	43,447
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock	0	23,395
Borrowings on unsecured line of credit	90,000	0
Repayments on unsecured line of credit	(135,000)	(185,000)
Principal payments on secured debt	(2,414)	(84,918)
Proceeds from the issuance of unsecured debt	0	299,901
Financing costs	(418)	(2,870)
Repurchase of common stock and restricted stock units	(1,517)	(1,209)
Proceeds from exercise of stock options	21	0
Dividends and distributions paid to common stockholders and common unitholders	(29,561)	(26,956)
Dividends and distributions paid to preferred stockholders and preferred unitholders	(3,313)	(3,313)
Net cash (used in) provided by financing activities	(82,202)	19,030
Net increase in cash and cash equivalents	60,157	118,976
Cash and cash equivalents, beginning of period	35,377	16,700
Cash and cash equivalents, end of period	95,534	135,676
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $10,042 and $7,175 as of March 31, 2014 and 2013, respectively	14,106	11,303
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	64,709	42,140
Tenant improvements funded directly by tenants	4,470	1,426
Assumption of secured debt in connection with property acquisitions	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net	0	422
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders	29,906	27,011
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders	1,656	1,694
Grant date fair value of share-based compensation awards	0	8,451
Exchange of common units of the Operating Partnership into shares of the Company’s common stock	$ 28	$ 0