Income Per Share of Common Stock (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income Per Share of Common Stock
Net income for basic and diluted income per common share (in dollars)	$ 2,757	$ 4,624
Weighted-average shares for basic income per common share	5,558,000	6,172,000
Effect of dilutive securities:
Employee and director stock options (in shares)	10,000	16,000
Adjusted weighted-average shares and assumed exercises for diluted income per common share	5,568,000	6,188,000
Basic net income per common share (in dollars per share)	$ 0.50	$ 0.75
Diluted net income per common share (in dollars per share)	$ 0.50	$ 0.75
Options
Anti-dilutive securities
Anti-dilutive shares of common stock excluded from the calculation of dilutive securities	9,900