Summary of Significant Accounting Policies (Details 2) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	[1]	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Income from continuing operations	$ 4,295	$ 3,695	$ 4,171	$ 1,529	$ 14,859	$ 2,965	$ 3,375	$ 1,047		$ 13,690	$ 22,246	$ 12,910
Less: Income allocated to unvested participating securities										256	370	231
Income from continuing operations available to common stockholders										13,434	21,876	12,679
Income from discontinued operations	$ 0	$ 0	$ 0	$ 0	$ (30)	$ 30,451	$ 1,159	$ 891		0	32,471	5,276
Less: Income allocated to unvested participating securities										0	541	94
Income from discontinued operations available to common stockholders										0	31,930	5,182
Net income available to common stockholders										$ 13,434	$ 53,806	$ 17,861
Denominator:
Denominator for basic earnings per share-weighted average shares	5,820	5,822	5,834	5,842	5,815	5,807	5,803	5,795		5,829	5,803	5,761
Effect of dilutive securities:
Stock options										0	4	10
Denominator for diluted earnings per share — adjusted weighted-average shares and assumed conversions	5,820	5,822	5,834	5,842	5,815	5,807	5,806	5,808		5,829	5,807	5,771
Basic earnings per share:
From continuing operations	$ 0.72	$ 0.62	$ 0.70	$ 0.26	$ 2.52	$ 0.50	$ 0.57	$ 0.18		$ 2.30	$ 3.77	$ 2.20
From discontinued operations	0	0	0	0	(0.01)	5.16	0.20	0.15		0	5.50	0.90
Basic earnings per share	0.72	0.62	0.70	0.26	2.51	5.66	0.77	0.33		2.30	9.27	3.10
Diluted earnings per share
From continuing operations	0.72	0.62	0.70	0.26	2.52	0.50	0.57	0.18		2.30	3.77	2.19
From discontinued operations	0	0	0	0	(0.01)	5.16	0.20	0.15		0	5.50	0.90
Diluted earnings per share	$ 0.72	$ 0.62	$ 0.70	$ 0.26	$ 2.51	$ 5.66	$ 0.77	$ 0.33		$ 2.30	$ 9.27	$ 3.09

[1] March 31, 2017 quarterly data have been reclassified to conform with current presentation.