Debt, Bank Debt and Credit Facilities (Details)	3 Months Ended							3 Months Ended						3 Months Ended				3 Months Ended							0 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Mar. 31, 2013 U S Revolver [Member] USD ($)	Mar. 31, 2012 U S Revolver [Member] USD ($)	Dec. 31, 2012 U S Revolver [Member] USD ($)	Mar. 31, 2013 U S Revolver Letter of Credit [Member] USD ($)	Dec. 31, 2012 U S Revolver Letter of Credit [Member] USD ($)	Mar. 31, 2013 Canadian Revolver [Member] CAD	Mar. 31, 2012 Canadian Revolver [Member] CAD	Mar. 31, 2013 Canadian Revolver [Member] USD ($)	Dec. 31, 2012 Canadian Revolver [Member] USD ($)	Mar. 31, 2013 Canadian Revolver Letter of Credit [Member] CAD	Dec. 31, 2012 Canadian Revolver Letter of Credit [Member] CAD	Mar. 31, 2013 Letter of Credit [Member] USD ($)	Dec. 31, 2012 Letter of Credit [Member] USD ($)	Mar. 31, 2013 Other Letter of Credit [Member] USD ($)	Dec. 31, 2012 Other Letter of Credit [Member] USD ($)	Mar. 31, 2013 Other Debt [Member] USD ($)	Mar. 31, 2012 Other Debt [Member] USD ($)	Mar. 31, 2013 Maximum [Member] U S Revolver [Member]	Mar. 31, 2013 Spinoff [Member] USD ($)	Apr. 16, 2013 Spinoff [Member] Subsequent Event [Member] USD ($)	Mar. 31, 2013 Spinoff [Member] Line of Credit [Member] USD ($)	Mar. 31, 2013 Spinoff [Member] Revolving Credit Facility [Member] USD ($)	May 01, 2013 Spinoff [Member] Notes Payable to Banks [Member] Subsequent Event [Member] USD ($)
Line of Credit Facility
Line of credit facility, maximum borrowing capacity			$ 3,000,000,000					50,000,000						$ 550,000,000							$ 800,000,000		$ 500,000,000	$ 300,000,000
Line of credit facility, expiration date (month, year)			December 2016					November 2013						June 2013
Letters of credit outstanding			0		0	59,000,000	59,000,000			0	0	10,000,000	10,000,000	550,000,000	418,000,000	441,000,000	275,000,000				0
Accounts Receivable Sales Facility
Balance as of beginning of period																		100,000,000	250,000,000
Repayments	0	(150,000,000)																0	(150,000,000)
Balance as of end of period																		100,000,000	100,000,000
Credit Facilities (Textual)
Debt to capitalization ratios as per terms of revolver			0.21		0.23															0.60
Borrowings from long-term lines of credit			0	0				0	0
Repayments of long-term lines of credit			0	0				0	0
Senior unsecured bonds of CST issued to us																						550,000,000
CST bonds exchanged in settlement of short-term borrowings																									550,000,000
Accounts Receivable Sales Facility (Textual)
Maximum eligible trade receivables																		$ 1,500,000,000
Extended term of accounts receivable sales facility																		July 2013