Shareholders' Equity (Details) (USD $)	0 Months Ended				1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	May 28, 2013	Aug. 21, 2012	Aug. 07, 2012	Nov. 01, 2011	Feb. 28, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Common stock repurchase, authorized amount				$ 15,000,000	$ 15,000,000
Stock repurchased during period, shares								253,000		639,000
Stock repurchased during period, aggregate purchase price								1,500,000		3,300,000
Common stock repurchase, remaining authorized amount								13,500,000
Retired shares of treasury stock			2,700,000
Retirement of treasury shares			15,100,000
Increase in quarterly cash dividend, percentage	10.00%
Quarterly cash dividend per share of common stock outstanding approved	$ 0.0275	$ 0.025				$ 0.0275	$ 0.0250	$ 0.0800	$ 0.0250
Dividend payment from cash on hand						759,000	686,000	2,200,000	686,000
Treasury Stock [Member]
Retirement of treasury shares			15,100,000
Common Stock [Member]
Retirement of treasury shares			27,000
Additional Paid-In Capital [Member]
Retirement of treasury shares			$ 15,100,000