Income Taxes (Other Disclosure) (Details) (USD $)	12 Months Ended									12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Divested Operations and Services [Member]	Dec. 31, 2010 Divested Operations and Services [Member]	Dec. 31, 2009 Divested Operations and Services [Member]	Dec. 31, 2012 Divested Operations and Services [Member]	Dec. 31, 2012 Federal Jurisdiction [Member]	Dec. 31, 2012 State Jurisdiction [Member]	Dec. 31, 2012 Additional Paid-In Capital [Member]	Dec. 31, 2011 Additional Paid-In Capital [Member]	Dec. 31, 2010 Additional Paid-In Capital [Member]
Operating Loss Carryforwards [Line Items]
Federal and State Income Tax Benefit From Sale of Business						$ 60,600,000
Other Tax Benefits From Sale of Business				6,800,000	4,400,000
Additional tax expense from sale of business						600,000
Deferred tax assets for capital loss carryovers				25,100,000			6,800,000
Valuation Allowance, Deferred Tax Asset, Change in Amount	(44,000,000)
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options	16,600,000	8,700,000	7,500,000
Tax benefit (detriment) related to equity compensation plans	5,130,000	816,000	(5,667,000)							5,130,000	816,000	(5,667,000)
Operating loss carryforwards								6,000,000	158,100,000
Deferred Taxes, Business Combination, Valuation Allowance, Available to Reduce Goodwill and Intangible Assets	$ 0