Discontinued Operations Assets Held for Sale and Discontinued Operations (Assets held for sale and discontinued operations) (Details) - Tennessee - Discontinued Operations, Disposed of by Sale [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	$ 605	$ 744	$ 0
Operating income	277	314	0
Net gain on disposal	191	(29)	0
Income tax provision	(187)	(112)	0
Income from discontinued operations, net of tax	$ 281	$ 173	$ 0