Schedule III - Real Estate and Accumulated Depreciation - Summarized Activity for Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance at beginning of period	$ 1,116,199	$ 1,070,606	$ 881,251
Acquisition of real estate	31,129		166,630
Additions during period	42,623	45,642	22,725
Write-off of assets as a result of involuntary conversion		(49)
Balance at end of period	1,189,951	1,116,199	1,070,606
Balance at beginning of period	90,462	73,714	58,174
Depreciation expense	18,956	16,765	15,540
Write-off of assets as a result of involuntary conversion		(17)
Balance at end of period	$ 109,418	$ 90,462	$ 73,714