Significant Accounting Policies (Stock Transactions - Options Exercised Tables) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Significant Accounting Policies [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	3,841
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 6,055
Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options	17,046
Tax deduction realized from options exercised	$ 513