Acquisition of Hotel Properties (Narrative) (Details) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2018 USD ($)	Mar. 31, 2018 property	Sep. 30, 2017 USD ($) property	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($) property	Dec. 31, 2017 property
Business Acquisition [Line Items]
Number of wholly owned properties acquired | property		2	2		2	5	3
Total revenue	$ 17,834			$ 14,252	$ 34,513	$ 24,613
Net income (loss)	2,886			4,925	3,672	2,575
Wholly Owned Properties Acquired [Member]
Business Acquisition [Line Items]
Total revenue	2,161			4,325	3,574	4,630
Net income (loss)	$ 639			$ 1,186	$ 1,167	$ 1,359
El Paso, Texas [Member] | Fairfield Inn & Suites [Member]
Business Acquisition [Line Items]
Purchase price			$ 16,400
Austin, Texas [Member] | Residence Inn [Member]
Business Acquisition [Line Items]
Purchase price			$ 22,400