Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended
	Sep. 30, 2018	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019	Dec. 31, 2018
Accounting Policies [Line Items]
Percentage of Operating Partnership Owned		99.10%
Number of Reportable Segments		1
Real Estate Held for Sale, net		$ 0			$ 0
Cash in Excess of FDIC Insured Amounts		24,000,000			52,700,000
Deferred Rent Receivables, Net		18,200,000			16,700,000
Deferred income tax liability		475,000			475,000
Income tax benefit (expense)		170,000	$ (50,000)
Proceeds From Issuance Of Common Stock		57,845,000	$ (93,000)
Lease liabilities		$ 19,551,000
ASU 2016-02 | Restatement
Accounting Policies [Line Items]
Right of use assets				$ 7,500,000
Lease liabilities				$ 7,500,000
September 2018 Forward Sales [Member]
Accounting Policies [Line Items]
Forward Contract Indexed to Issuer's Equity, Shares	3,500,000
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share	$ 55.20
Forward Contract Indexed to Issuer's Equity, Settlement Date	Sep. 03, 2019
Incremental Common Shares Attributable to Dilutive Effect of Equity Forward Agreements		766,675	0
Unbilled Revenues [Member]
Accounting Policies [Line Items]
Accounts Receivable, Gross		$ 3,800,000			$ 3,300,000