Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows From Operating Activities
Net income	$ 117,253	$ 118,253	$ 107,250
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	168,508	160,710	155,211
Amortization of non-cash items within interest expense	7,215	1,039	739
Amortization of acquired above and below-market leases, net	(6,120)	(5,721)	(8,795)
Amortization of acquired below-market ground leases	7,831	7,831	7,831
Straight-lining of rental revenue	(22,107)	(26,544)	(30,147)
Equity based compensation	18,785	14,100	9,729
Settlement of derivative contracts	0	(15,695)	0
Loss on early extinguishment of debt	0	2,157	552
Increase (decrease) in cash flows due to changes in operating assets and liabilities:
Security deposits	10,717	(97)	(1,707)
Tenant and other receivables	(1,275)	(5,787)	(3,760)
Deferred leasing costs	(26,899)	(31,743)	(22,622)
Prepaid expenses and other assets	(781)	(7,893)	(3,289)
Accounts payable and accrued expenses	1,993	(25,103)	2,939
Deferred revenue and other liabilities	3,902	8,695	824
Net cash provided by operating activities	279,022	194,202	214,755
Cash Flows From Investing Activities
Short-term investments	(400,000)	0	0
Additions to building and improvements	(243,022)	(222,979)	(181,923)
Development costs	(1)	(34)	(453)
Net cash used in investing activities	(643,023)	(223,013)	(182,376)
Cash Flows From Financing Activities
Proceeds from unsecured revolving credit facility	0	0	50,000
Repayments of unsecured revolving credit facility	0	0	(90,000)
Proceeds from mortgage notes payable	160,000	315,000	50,000
Repayment of mortgage notes payable	(266,613)	(346,615)	(32,305)
Proceeds from senior unsecured notes	335,000	115,000	0
Repayment of unsecured term loan	0	(265,000)	0
Proceeds from unsecured revolving credit and term loan facility	0	265,000	0
Deferred financing costs	(1,980)	(13,299)	(3,006)
Net proceeds from the sale of common stock	4,749	0	611,206
Private perpetual preferred unit distributions	(936)	(936)	(936)
Dividends paid to common stockholders	(70,854)	(66,789)	(55,812)
Distributions paid to noncontrolling interests in the operating partnership	(54,749)	(59,238)	(58,206)
Net cash provided by (used in) financing activities	104,617	(56,877)	470,941
Net (decrease) in cash and cash equivalents and restricted cash	(259,384)	(85,688)	503,320
Cash and cash equivalents and restricted cash—beginning of period	530,197	615,885	112,565
Cash and cash equivalents and restricted cash—end of period	270,813	530,197	615,885
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	464,344	554,371	46,685
Restricted cash at beginning of period	65,853	61,514	65,880
Cash and cash equivalents and restricted cash—end of period	204,981	464,344	554,371
Restricted cash at end of period	65,832	65,853	61,514
Cash and cash equivalents and restricted cash	530,197	615,885	112,565
Supplemental disclosures of cash flow information:
Cash paid for interest	74,160	66,911	69,062
Interest capitalized	1,596	459	0
Cash paid for income taxes	4,847	5,783	6,238
Non-cash investing and financing activities:
Building and improvements included in accounts payable and accrued expenses	85,242	71,769	66,620
Write-off of fully depreciated assets	39,665	19,136	15,381
Conversion of operating partnership units and Class B shares to Class A shares	$ 70,779	$ 23,435	$ 23,678