Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operating Activities
Net income	$ 118,253	$ 107,250	$ 79,928
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	160,710	155,211	171,474
Amortization of non-cash items within interest expense	1,039	739	1,698
Amortization of acquired above and below-market leases, net	(5,721)	(8,795)	(19,353)
Amortization of acquired below-market ground leases	7,831	7,831	7,996
Straight-lining of rental revenue	(26,544)	(30,147)	(21,220)
Equity based compensation	14,100	9,729	5,483
Settlement of derivative contracts	(15,695)	0	0
Loss on early extinguishment of debt	2,157	552	1,749
Increase (decrease) in cash flows due to changes in operating assets and liabilities (excluding the effect of acquisitions):
Restricted cash	(2,843)	2,121	2,954
Tenant and other receivables	(5,787)	(3,760)	4,963
Deferred leasing costs	(31,743)	(22,622)	(31,367)
Prepaid expenses and other assets	(7,893)	(3,289)	(1,956)
Accounts payable and accrued expenses	(25,104)	2,939	(2,674)
Deferred revenue and other liabilities	8,695	824	3,512
Net cash provided by operating activities	191,455	218,583	203,187
Cash Flows From Investing Activities
Decrease (increase) in restricted cash for investing activities	(1,592)	538	(119)
Additions to building and improvements	(222,979)	(181,923)	(141,685)
Development costs	(34)	(453)	(512)
Net cash used in investing activities	(224,605)	(181,838)	(142,316)
Cash Flows From Financing Activities
Proceeds from unsecured revolving credit facility	0	50,000	655,000
Repayments of unsecured revolving credit facility	0	(90,000)	(615,000)
Proceeds from mortgage notes payable	315,000	50,000	0
Repayment of mortgage notes payable	(346,615)	(32,305)	(146,918)
Proceeds from senior unsecured notes	115,000	0	350,000
Proceeds from unsecured term loan	0	0	265,000
Repayment of unsecured term loan	(265,000)	0	0
Proceeds from unsecured revolving credit and term loan facility	265,000	0	0
Repayments of secured term loan and credit facility	0	0	(470,000)
Deferred financing costs	(13,299)	(3,006)	(6,100)
Net proceeds from the sale of common stock	0	611,206	0
Private perpetual preferred unit distributions	(936)	(936)	(936)
Dividends paid to common stockholders	(66,789)	(55,812)	(39,183)
Distributions paid to noncontrolling interests in the operating partnership	(59,238)	(58,206)	(51,781)
Net cash provided by (used in) financing activities	(56,877)	470,941	(59,918)
Net increase (decrease) in cash and cash equivalents	(90,027)	507,686	953
Cash and cash equivalents—beginning of period	554,371	46,685	45,732
Cash and cash equivalents—end of period	464,344	554,371	46,685
Supplemental disclosures of cash flow information:
Cash paid for interest	66,911	69,062	64,808
Interest capitalized	459	0	0
Cash paid for income taxes	5,783	6,238	4,465
Non-cash investing and financing activities:
Building and improvements included in accounts payable and accrued expenses	71,769	66,620	51,315
Derivative instruments at fair values included in prepaid expenses and other assets	0	614	0
Derivative instruments at fair values included in accounts payable and accrued expenses	436	5,591	1,922
Conversion of operating partnership units and Class B shares to Class A shares	$ 23,435	$ 23,678	$ 62,003