2. Summary of Significant Accounting Policies (Detail) - Table of Stock-Based Compensation (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Total fair value of options vested	$ 90,000	$ 178,000	$ 248,000
Total compensation cost, options and restricted stock	155,000	202,000	236,000
Tax benefit recognized	53,000	22,000	32,000
Net compensation cost, options and restricted stock	102,000	180,000	204,000
Total compensation cost for nonvested option awards not yet recognized	59,000	62,000	216,000
Total compensation cost for restricted stock not yet recognized	$ 152,000	$ 151,000	$ 158,000
Employee Stock Option [Member]
Weighted average years for compensation cost to be recognized	1.07	0.8	1.1
Restricted Shares [Member]
Weighted average years for compensation cost to be recognized	1.4	1.6	1.7