CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (8,180)	$ 6,678	$ 30,335
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	92,266	83,828	89,400
Net amortization of debt premiums, discounts and issuance costs	9,771	9,593	10,740
Amortization of acquired real estate leases	144,826	167,192	197,978
Amortization of deferred leasing costs	7,878	6,887	5,973
Gain on sale of real estate	(78,354)	(10,855)	(105,131)
Loss on impairment of real estate	62,420	2,954	22,255
Loss on early extinguishment of debt	9,694	2,701	769
Straight line rental income	(15,368)	(16,079)	(27,507)
Other non-cash expenses, net	1,782	2,229	2,011
Loss on equity securities, net	0	0	44,007
Equity in net losses of investees	2,501	1,193	1,259
Change in assets and liabilities:
Rents receivable	2,663	(3,962)	12,586
Deferred leasing costs	(19,769)	(12,128)	(27,971)
Other assets	1,538	2,505	3,266
Accounts payable and other liabilities	7,151	(8,081)	(19,333)
Due to related persons	673	(1,027)	(27,746)
Net cash provided by operating activities	221,492	233,628	215,329
CASH FLOWS FROM INVESTING ACTIVITIES:
Real estate acquisitions	(563,447)	(47,215)	(2,905)
Real estate improvements	(100,141)	(81,762)	(62,676)
Proceeds from sale of properties, net	219,980	102,211	829,794
Proceeds from repayment of mortgage note receivable	0	2,880	0
Net cash (used in) provided by investing activities	(442,985)	(22,987)	877,819
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of mortgage notes payable	(72,541)	(155,367)	(12,054)
Repayment of unsecured term loans	0	0	(388,000)
Repayment of senior unsecured notes	(610,000)	(400,000)	(350,000)
Proceeds from issuance of senior unsecured notes, net	1,041,809	408,932	0
Borrowings on unsecured revolving credit facility	755,000	561,467	430,000
Repayments on unsecured revolving credit facility	(755,000)	(561,467)	(605,000)
Payment of debt issuance costs	(2,744)	(1,492)	0
Repurchase of common shares	(1,003)	(434)	(473)
Distributions to common shareholders	(106,368)	(106,121)	(105,868)
Net cash provided by (used in) financing activities	249,153	(254,482)	(1,031,395)
Increase (decrease) in cash, cash equivalents and restricted cash	27,660	(43,841)	61,753
Cash, cash equivalents and restricted cash at beginning of period	56,855	100,696	38,943
Cash, cash equivalents and restricted cash at end of period	84,515	56,855	100,696
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid	103,200	100,083	131,735
Income taxes paid	299	1,377	491
NON-CASH INVESTING ACTIVITIES:
Real estate improvements accrued, not paid	18,492	11,981	11,457
Real estate acquisition	(13,031)	0	0
Capitalized interest	795	199	26
SUPPLEMENTAL DISCLOSURE OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	83,026	42,045	93,744
Restricted cash	1,489	14,810	6,952
Total cash, cash equivalents and restricted cash shown in the consolidated statements of cash flows	84,515	56,855	100,696
AIC
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Distribution of earnings from Affiliates Insurance Company	0	0	2,438
CASH FLOWS FROM INVESTING ACTIVITIES:
Distributions in excess of earnings	11	287	6,562
Unconsolidated Joint Ventures
CASH FLOWS FROM INVESTING ACTIVITIES:
Distributions in excess of earnings	612	612	2,370
RMR Inc
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sale of The RMR Group Inc. common shares, net	$ 0	$ 0	$ 104,674