Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Numerator:
Net income attributable to common shareholders	$ 4,563	$ 4,099	$ 13,890	$ 12,745
Denominator:
Denominator for basic earnings per share-weighted-average shares	11,827	11,886	11,778	11,824
Effect of dilutive securities-Stock options	101	125	114	183
Denominator for diluted earnings per share-adjusted weighted-average shares	11,928	12,011	11,892	12,007
Earnings per share attributable to common shareholders:
Basic	$ 0.39	$ 0.35	$ 1.18	$ 1.08
Diluted	$ 0.38	$ 0.34	$ 1.17	$ 1.06