Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	0 Months Ended		12 Months Ended					0 Months Ended	1 Months Ended
	Feb. 06, 2012	Nov. 29, 2010	Dec. 31, 2011 months days		Dec. 31, 2010		Dec. 31, 2009	Dec. 20, 2010 IPO [Member]	Jun. 30, 2011 2005 Facility [Member]	Jun. 30, 2011 CCS Credit Facility [Member]	Jun. 30, 2011 New Credit Facility [Member]
Summary Of Significant Accounting Policies [Line Items]
Net deferred financing costs			$ 6,600,000		$ 2,300,000
Customer payment terms (in days)			14
Maximum allocation period (in year)			1
Minimum percentage of likelihood required to recognize uncertain income tax position			50.00%
Maturity of cash equivalent, max (in months)			3
Deferred financing fees	600,000
Securitized accounts receivable facility			500,000,000
Impact on total assets of adoption of SFAS 156					218,000,000
Impact on total liabilities of adoption of SFAS 156					218,000,000
Impact on cash flows of adoption of SFAS 156					218,000,000
Impact on revenues of adoption of SFAS 156					27,200,000
Short-term debt outstanding			280,000,000	[1]	144,000,000	[1]
Premium on purchased receivables			23,000,000		26,300,000
Advertising expense			8,900,000		8,200,000		9,800,000
Foreign exchange gains recognized			600,000		500,000		900,000
Options granted have vesting range, maximum			six		six
Options granted have vesting range, minimum					one
Wrote-off deferred debt issuance costs									1,700,000	1,000,000
Debt issuance costs											7,200,000
Company's consolidated revenue percentage			11.00%		11.00%		10.00%
Concentration, description of terms			Agreements with the major oil company partners typically have initial terms of five to ten years with current remaining terms ranging from less than one year up to ten years
Common stock, shares issued			113,741,883		111,522,354			430,961
Net proceeds from initial public offering					9,560,000			9,560,000
Common shares sold by selling shareholders in initial public offering								14,145,289
Convertible preferred stock			0		0			43,575,148
Cash dividends received								7,600,000
Compensation expense								$ 23,000,000
Shares of restricted stock and stock options								1,930,972
Stock split ratio		two and one-half for one

[1] The Company is party to a receivables purchase agreement (Securitization Facility) that was amended and restated for the fourth time as of October 29, 2007 and which has been amended seven times since then to add or remove purchasers, extend the facility termination date and remove all financial covenants. The current purchase limit under the securitization facility is $500 million. The facility was amended for the seventh time on February 6, 2012 to add a new purchaser and extend the facility termination date to February 4, 2013. There is a program fee equal to the Commercial Paper Rate of 0.34%, plus 0.90% as of December 31, 2011. The unused facility fee is payable at a rate of 0.50% per annum as of December 31, 2011. The Securitization Facility provides for certain termination events, which includes nonpayment, upon the occurrence of which the administrator may declare the facility termination date to have occurred, may exercise certain enforcement rights with respect to the receivables, and may appoint a successor servicer, among other things.