Equity Investment in Select Income REIT (Details) - USD ($) $ in Thousands			9 Months Ended		12 Months Ended
	Oct. 09, 2018	Jul. 05, 2017	Oct. 09, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity method investment, other than temporary impairment					$ 0	$ 15,180	$ 0
Equity in net losses of investees					(1,259)	(2,269)	(13)
Unrealized gain (loss) from investees						(40)	9,428
Distribution of earnings from Affiliates Insurance Company					2,438	0	0
Gain (loss) on issuance of shares by Select Income REIT					0	29	72
SIR
Schedule of Equity Method Investments [Line Items]
Percentage of outstanding shares owned	27.80%		27.80%
Equity in net losses of investees			$ 24,358				21,584
Unrealized gain (loss) from investees			28				8,967
Accretion of equity in earnings			3,233				2,944
Distribution of earnings from Affiliates Insurance Company			$ 38,124				$ 50,832
SIR | SIR
Schedule of Equity Method Investments [Line Items]
Equity in net losses of investees				$ 882		608
Issuance of shares, net (in shares)			63,157				59,502
Gain (loss) on issuance of shares by Select Income REIT			$ 29			$ 72
Common Shares
Schedule of Equity Method Investments [Line Items]
Issuance of shares, net (in shares)						23,281,738	6,976,757
Underwritten Public Offering
Schedule of Equity Method Investments [Line Items]
Number of shares sold (in shares)		6,250,000
Underwritten Public Offering | Common Shares
Schedule of Equity Method Investments [Line Items]
Number of shares sold (in shares)	24,918,421
Equity method investment, other than temporary impairment						$ 18,665
Discontinued Operations | SIR
Schedule of Equity Method Investments [Line Items]
Equity method investment, other than temporary impairment					0	18,665	$ 0
Equity in net losses of investees					0	24,358	21,584
Gain (loss) on issuance of shares by Select Income REIT					$ 0	$ 29	$ 72