CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 134,592	$ 149,970	$ 152,146
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on disposition of properties	(81,965)	(89,063)	(14,360)
Depreciation and amortization	70,011	60,751	49,645
Distributions of operating income from unconsolidated affiliates	7,256	12,291	9,579
Equity in earnings and gains of unconsolidated affiliates	(39,449)	(37,330)	(111,578)
Stock compensation expense	13,695	7,438	6,744
Amortization of financing costs	3,204	3,537	3,003
Impairment of asset	0	5,000	0
Other, net	(8,095)	(6,483)	(3,812)
Changes in assets and liabilities:
Other liabilities	26,532	5,354	3,099
Prepaid expenses and other assets	(11,677)	12,690	852
Rents receivable, net	(4,847)	(5,673)	(8,097)
Accounts payable and accrued expenses	1,912	(6,168)	(686)
Cash in escrow	591	1,284	(4,016)
Net cash provided by operating activities	111,760	113,598	82,519
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of real estate	(495,644)	(338,700)	(256,453)
Development and property improvement costs	(149,434)	(164,315)	(140,118)
Issuance of notes receivable	(157,352)	(48,500)	(31,169)
Proceeds from the disposition of properties	150,378	168,895	31,188
Investments in and advances to unconsolidated affiliates	(72,098)	(24,168)	(156,972)
Return of capital from unconsolidated affiliates	54,444	11,892	74,371
Proceeds from notes receivable	42,819	15,984	18,095
Proceeds from disposition of properties of unconsolidated affiliates	24,586	38,392	190,356
Deferred leasing costs	(7,515)	(8,207)	(3,914)
Change in control of previously consolidated affiliate	(2,578)	0	0
Deposits for properties under contract	1,424	(5,776)	6,100
Net cash used in investing activities	(610,970)	(354,503)	(268,516)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on mortgage and other notes	(936,654)	(383,238)	(176,323)
Proceeds received on mortgage and other notes	888,787	507,659	284,303
Proceeds from issuance of Common Shares, net of issuance costs of $9,238, $1,150 and $2,112 respectively	450,130	63,234	357,459
Capital contributions from noncontrolling interests	295,108	35,489	57,970
Distributions to noncontrolling interests	(105,994)	(84,610)	(221,330)
Dividends paid to Common Shareholders	(91,334)	(86,353)	(53,210)
Deferred financing and other costs	(11,678)	(4,376)	(3,672)
Loan proceeds held as restricted cash	9,874	48,676	79,191
Purchase of convertible notes payable	0	(380)	0
Net cash provided by financing activities	498,239	96,101	324,388
(Decrease) increase in cash and cash equivalents	(971)	(144,804)	138,391
Cash and cash equivalents, beginning of year	72,776	217,580	79,189
Cash and cash equivalents, end of year	71,805	72,776	217,580
Supplemental disclosure of cash flow information
Cash paid during the period for interest, net of capitalized interest of $21,109, $16,447 and $12,650, respectively	42,279	47,960	46,542
Cash paid for income taxes, net of refunds received of $0, $0 and $2,045, respectively	2,036	2,038	(1,772)
Supplemental disclosure of non-cash investing activities
Acquisition of real estate through assumption of debt	120,672	91,885	29,794
Acquisition of real estate through issuance of OP Units	29,336	0	38,937
Acquisition of capital lease obligation	76,461	0	0
Mortgage debt financed at time of acquisition	63,900	0	0
Assumption of accounts payable and accrued expenses through acquisition of real estate	3,587	0	0
Assumption of prepaid expenses and other assets through acquisition of real estate	2,226	0	0
Disposition of air rights through issuance of notes receivable	0	(29,539)	0
Acquisition of real estate through assumption of restricted cash	0	(28,912)	0
Acquisition of real estate through conversion of notes receivable	0	13,386	38,000
Disposition of real estate through forgiveness of debt	0	0	(22,865)
Investments in and advances to unconsolidated affiliates through issuance of OP Units	0	0	5,114
Change in control of previously consolidated investment
Real estate, net	90,559	0	0
Investments in and advances to unconsolidated affiliates	(21,421)	0	0
Other assets and liabilities	3,997	0	0
Noncontrolling interest	(75,713)	0	0
Cash removed in de-consolidation of previously consolidated investment	$ (2,578)	$ 0	$ 0