Summary of Operations and Significant Accounting Policies (Reconciliation of Shares Used in Calculating Basic and Diluted Earnings Per Share) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Summary of Operations and Significant Accounting Policies [Abstract]
Basic	54,806,694	55,146,901	55,332,449	54,786,499
Effect of assumed exercised options		2,003,355		1,862,661
Diluted	54,806,694	57,150,256	55,332,449	56,649,160