Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Comprehensive income attributable to common stockholders
Net (loss) income	$ (1,579)	$ 515	$ 2,912
Other comprehensive income/(loss):
Unrealized (loss) gain on available-for-sale securities	(100)	62	(188)
Benefit plan adjustments	404	(371)	(1,301)
Benefit plan reclassification for losses included in net income	0	0	536
Unrealized interest rate swap gains/(losses)	970	1,040	678
Other comprehensive income (loss) before taxes	1,602	945	(41)
Benefit (provision) for income taxes related to other comprehensive (loss) income items	(627)	(282)	38
Other comprehensive income (loss)	975	663	(3)
Comprehensive (loss) income	(604)	1,178	2,909
Comprehensive (loss) income attributable to non-controlling interests	(24)	(43)	(38)
Comprehensive (loss) income attributable to common stockholders	(580)	1,221	2,947
SERP
Other comprehensive income/(loss):
Benefit plan adjustments	328	214	$ 234
Benefit plan reclassification for losses included in net income	$ 313	$ 214