Earnings and Dividends Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Earnings per Share, Basic and Diluted
Net income loss available to common stockholders basic	$ 2,485	$ 1,953	$ 4,530	$ 3,211
Basic net income and earnings per share	14,615,913	14,334,116	14,571,642	14,324,040
Basic net income and earnings per share, Amount	$ 0.17	$ 0.14	$ 0.31	$ 0.22
Effect of dilutive securities and notes:
Common stock equivalents arising from stock options and employee stock purchase plan
Common stock equivalents arising from stock options and employee stock purchase plan, shares	289	158	250	134
Common stock equivalents arising from stock options and employee stock purchase plan per share
Subordinated convertible promissory notes	82	95	169	190
Subordinated convertible promissory notes	2,306	2,650	2,348	2,659
Subordinated convertible promissory notes per, share	$ (0.02)	$ (0.02)	$ (0.04)	$ (0.02)
Net income loss available to common stockholders diluted	$ 2,567	$ 2,048	$ 4,699	$ 3,401
Diluted net income and earnings per share	17,211,339	17,141,633	17,169,674	17,117,440
Earnings Per Share, Diluted	$ 0.15	$ 0.12	$ 0.27	$ 0.20