Significant Accounting Policies - EPS (Details) - $ / shares	1 Months Ended				12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 28, 2017
Schedule of reconciliation of shares used to calculate basic and diluted earnings per share
Weighted average shares outstanding used to compute basic earnings per share					10,678,000	10,610,000	10,588,000
Incremental shares issuable upon the assumed exercise of stock options					39,000	5,000	6,000
Unvested restricted stock					482,000	230,000	146,000
Shares used to compute diluted earnings per share					11,199,000	10,845,000	10,740,000
Common stock, shares authorized	20,000,000				20,000,000	20,000,000
Common stock, par value	$ 0.01				$ 0.01	$ 0.01
Common stock, shares issued	11,167,425				11,167,425	11,093,489
Common stock, shares outstanding	11,167,425				11,167,425	11,093,489
Preferred stock, shares authorized	8,000,000				8,000,000	8,000,000
Preferred stock, shares issued	0				0	0
Preferred stock, shares outstanding	0				0	0
Dividends declared, per share								$ 1.00
Dividends paid, per share	$ 0.25	$ 0.25	$ 0.25	$ 0.25
Antidilutive stock options					0	0	0