Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows From Operating Activities
Net income	$ 48,242	$ 50,504
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	79,351	81,378
Amortization of non-cash items within interest expense	3,069	487
Amortization of acquired above- and below-market leases, net	(2,719)	(2,548)
Amortization of acquired below-market ground leases	3,916	3,916
Straight-lining of rental revenue	(11,662)	(13,396)
Equity based compensation	9,211	6,967
Unrealized loss from derivative financial instruments	0	(6,003)
Increase (decrease) in cash flows due to changes in operating assets and liabilities:
Security deposits	(4,278)	2,487
Tenant and other receivables	6,601	(1,452)
Deferred leasing costs	(10,349)	(12,766)
Prepaid expenses and other assets	2,351	(1,489)
Accounts payable and accrued expenses	(2,691)	(10,909)
Deferred revenue and other liabilities	(11,355)	(4,832)
Net cash provided by operating activities	109,687	92,344
Cash Flows From Investing Activities
Short-term investments	(400,000)	0
Development costs	(1)	(27)
Additions to building and improvements	(98,567)	(103,614)
Net cash used in investing activities	(498,568)	(103,641)
Cash Flows From Financing Activities
Proceeds from mortgage notes payable	160,000	315,000
Repayment of mortgage notes payable	(264,771)	(342,703)
Proceeds from unsecured revolving credit facility and term loan	335,000	0
Proceeds from the sale of common stock	4,749	0
Deferred financing costs	(1,902)	(4,508)
Private perpetual preferred unit distributions	(468)	(468)
Dividends paid to common stockholders	(34,792)	(33,118)
Distributions paid to non-controlling interests in the operating partnership	(28,616)	(29,822)
Net cash provided by (used in) financing activities	169,200	(95,619)
Net decrease in cash and cash equivalents and restricted cash	(219,681)	(106,916)
Cash and cash equivalents and restricted cash—beginning of period	530,197	615,885
Cash and cash equivalents and restricted cash—end of period	310,516	508,969
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	464,344	554,371
Restricted cash at beginning of period	65,853	61,514
Cash and cash equivalents at end of period	251,797	440,958
Restricted cash at end of period	58,719	68,011
Supplemental disclosures of cash flow information:
Cash paid for interest	35,956	35,751
Cash paid for income taxes	2,703	3,014
Non-cash investing and financing activities:
Building and improvements included in accounts payable and accrued expenses	96,439	72,363
Derivative instruments at fair values included in prepaid expenses and other assets	6,018	0
Derivative instruments at fair values included in accounts payable and accrued expenses	0	11,947
Conversion of operating partnership units and Class B shares to Class A shares	$ 25,845	$ 9,134