Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities:
Net income	$ 37,044	$ 22,038	$ 146,133
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of building and building improvements	80,394	60,120	55,982
Amortization of leasing costs and intangibles, including ground leasehold interests and leasing costs	73,031	59,048	60,601
Amortization of (below) above market leases	(3,201)	(685)	1,689
Amortization of deferred financing costs and debt premium	5,562	3,071	2,444
Amortization of swap interest	126	126	0
Deferred rent	(19,519)	(8,571)	(11,372)
Deferred rent, ground lease	1,640		0
Termination fee revenue - receivable from tenant, net	(6,000)	(3,114)	(12,845)
Gain from sale of depreciable operating property	(29,940)	(1,231)	(116,382)
(Gain) loss on fair value of earn-out	(1,461)	0	0
Unrealized loss on interest rate swap	0	2	68
(Gain) loss from investment in unconsolidated entities	5,307	2,254	2,065
(Gain) loss from investments	307	0	0
Impairment provision	30,734	0	8,460
Performance distribution allocation (non-cash)	(2,604)	0	0
Stock-based compensation	2,623	38	173
Change in operating assets and liabilities:
Deferred leasing costs and other assets	(7,775)	(13,503)	3,332
Restricted reserves	14	57	(175)
Accrued expenses and other liabilities	(9,505)	3,463	1,098
Due to affiliates, net	4,072	(2,254)	826
Net cash provided by operating activities	160,849	120,859	142,097
Investing Activities:
Cash acquired in connection with the Mergers, net of acquisition costs	25,320	0	0
Acquisition of properties, net	(38,775)	(182,250)	(134,130)
Proceeds from disposition of properties	139,446	11,442	394,502
Real estate acquisition deposits	(1,047)	(3,350)	(1,350)
Reserves for tenant improvements	1,039	(357)	0
Improvements to real estate	0	0	(760)
Payments for construction in progress	(46,346)	(24,398)	(11,293)
Investment in unconsolidated joint venture	0	(3,274)	0
Distributions of capital from investment in unconsolidated entities	14,603	7,691	7,599
Distributions of capital from investment in unconsolidated entities	(8,422)	0	0
Net cash provided by (used in) investing activities	85,818	(194,496)	254,568
Financing Activities:
Proceeds from borrowings - BOA Loan	0	0	375,000
Proceeds from borrowings - Term Loan	627,000	0	0
Proceeds from borrowings - Revolver Loan	315,854	0	0
Proceeds from borrowings - Revolver Loan - EA-1	0	96,100	54,000
Principal payoff of secured indebtedness - Revolver Loan	(104,439)	0	0
Principal payoff of secured indebtedness - Mortgage Debt	0	(18,954)	(41,493)
Principal payoff of secured indebtedness - Unsecured Credit Facility - EA-1	(715,000)	(106,253)	(441,256)
Partial principal payoff of TW Telecom loan	0	0	(324)
Principal amortization payments on secured indebtedness	(6,577)	(6,494)	(6,491)
Deferred financing costs	(5,737)	(24)	(3,329)
Offering costs	(2,384)	0	0
Issuance of perpetual convertible preferred shares	0	125,000	0
Repurchase of common stock	(200,013)	(83,574)	(98,906)
Repurchase of noncontrolling interest	(53)	0	0
Issuance of common stock, net of discounts and underwriting costs	8,826	0	0
Payment of offering costs - preferred shares	0	(4,959)	0
Dividends paid on preferred units subject to redemption	(8,188)	(1,228)	0
Distributions to noncontrolling interests	(16,865)	(4,737)	(4,737)
Distributions to common stockholders	(90,116)	(71,822)	(71,124)
Net cash used in financing activities	(197,692)	(76,945)	(238,660)
Net increase (decrease) in cash, cash equivalents and restricted cash	48,975	(150,582)	158,005
Cash, cash equivalents and restricted cash at the beginning of the period	64,285	214,867	56,862
Cash, cash equivalents and restricted cash at the end of the period	113,260	64,285	214,867
Supplemental disclosure of cash flow information:
Cash paid for interest	65,040	50,736	48,253
Supplemental disclosures of non-cash investing and financing transactions:
Goodwill -Self Administration Transaction	0	229,948	0
Affiliates - receivables and other related party assets acquired in Self Administration Transaction	0	19,878	0
Increase in distributions payable to common stockholders	3,293	3,792	32
Increase in distributions payable to noncontrolling interests	1,355	0	0
Common stock issued pursuant to the distribution reinvestment plan	41,060	40,838	49,541
Increase in redemptions payable	96,648	0	20,382
Issuance of stock dividends	14,139	0	0
Limited partnership units issued in exchange for net assets acquired in Self Administration Transaction	25,000	205,000	0
Due to affiliates- Self Administration Transaction	0	41,114	0
Other liabilities assumed in Self Administration Transaction	0	7,951	0
Decrease in fair value swap agreement	(22,303)	(5,427)	(6,795)
Net assets acquired in Merger in exchange for common shares	751,277	0	0
Implied EA-1 common stock and operating partnership units issued in exchange for net assets acquired in Merger	751,277	0	0
Operating lease right-of-use assets obtained in exchange for lease liabilities upon adoption of ASC 842	16,919
Distributions to redeemable noncontrolling interests attributable to common stockholders as reflected on the consolidated statements of operations	$ 0	$ 355	$ 356