Commitments and Contingencies (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) agreement	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($) agreement
Loss Contingencies [Line Items]
Management fees incurred	$ 524	$ 440	$ 1,019	$ 764
Incentive management fee	116	8	$ 181	33
Management agreement renewal additional term			1 year
Management agreement written notice of termination period			90 days
Franchise costs	1,295	947	$ 2,517	1,615
Office Building [Member]
Loss Contingencies [Line Items]
Lease expense	$ 39	39	$ 78	77
Number of new leases entered into during period | agreement					3
Rent expense					$ 154
Minimum [Member]
Loss Contingencies [Line Items]
Management fee percent			3.00%
Management agreement term			1 year
Franchise fee percent			3.30%
Other franchiser programs and service fee percent			2.50%
Franchise agreement term			10 years
Minimum [Member] | Office Building [Member]
Loss Contingencies [Line Items]
Lease expiration					Dec. 31, 2019
Maximum [Member]
Loss Contingencies [Line Items]
Management fee percent			3.50%
Incentive fee percent			5.00%
Management agreement term			3 years
Franchise fee percent			5.50%
Other franchiser programs and service fee percent			6.00%
Franchise agreement term			25 years
Maximum [Member] | Office Building [Member]
Loss Contingencies [Line Items]
Lease expiration					Dec. 31, 2021
Land [Member]
Loss Contingencies [Line Items]
Number of land lease agreements related to properties owned | agreement			0
Lease expense		$ 0		$ 9