Acquisition and Purchase Price Allocation - Hotel Kranichhohe (Details) $ / shares in Units, € in Thousands, $ in Thousands			6 Months Ended	12 Months Ended
	Dec. 21, 2016 USD ($) room item	Dec. 21, 2016 EUR (€) item	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 21, 2016 EUR (€) room
Business Combination, Consideration Transferred.
Cash paid			$ 390
Total purchase price consideration			4,517
Gain recognized on purchase			$ 803
Hotel Kranichhöhe
Business Acquisition
Number of Rooms in Hotel | room	107					107
Number of food and beverage outlets | item	3	3
Number of meeting rooms | item	18	18
Number of indoor courts | item	2	2
Number of outdoor courts | item	2	2
Business Acquisition, Pro Forma Information
Revenues				$ 57,555	$ 46,859
Net income				$ 6,772	$ 3,684
Weighted Average Number of Shares Outstanding
Basic | shares				8,838,984	8,822,488
Diluted | shares				9,498,578	9,259,553
Earnings Per Share, Basic and Diluted
Basic | $ / shares				$ 0.77	$ 0.42
Diluted | $ / shares				$ 0.71	$ 0.40
Hotel Kranichhöhe | Other Income
Business Combination, Consideration Transferred.
Gain recognized on purchase	$ 124	€ 117
Hotel Kranichhöhe | Final Fair Value at Acquisition Date
Business Combination, Consideration Transferred.
Cash paid	957	900
Loan	4,251	4,000
Total purchase price consideration	5,208	4,900
Gain recognized on purchase	124	€ 117
Total	5,332					€ 5,017
Fair value assigned to assets acquired:
Land	1,792					1,686
Buildings	2,508					2,360
Property & equipment	494					465
Inventory	538					506
Total	$ 5,332					€ 5,017