Derivative Financial Instruments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended									6 Months Ended		12 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2011	May 06, 2011	Jun. 30, 2011 Term B Loan Facility [Member]	May 06, 2011 Term B Loan Facility [Member]	Dec. 31, 2010 Term B Loan Facility [Member]	Jun. 30, 2011 Senior Unsecured Notes Due 2021 [Member]	May 31, 2011 Senior Unsecured Notes Due 2021 [Member]	May 06, 2011 Senior Unsecured Notes Due 2021 [Member]	Dec. 31, 2010 Senior Unsecured Notes Due 2021 [Member]	Jun. 30, 2011 Swap Derivative 4 Point 33 Percent Maturing January 2, 2012 [Member]		Dec. 31, 2010 Swap Derivative 4 Point 33 Percent Maturing January 2, 2012 [Member]		Jun. 30, 2011 Swap Derivative 1 Point 92 Percent Maturing January 2, 2012 [Member]		Dec. 31, 2010 Swap Derivative 1 Point 92 Percent Maturing January 2, 2012 [Member]
Derivative [Line Items]
Notional Value		$ 1,400								$ 400		$ 400		$ 200		$ 200
Interest rate, stated percentage						5.875%	5.875%	5.875%	5.875%
Senior credit facility		516	0	275	508
Notional Value, No Longer Designated as Cash Flow Hedges		275								75				200
Derivative Interest Expense	$ 3
Fixed Rate										4.33%	[1]	4.33%	[1]	1.92%	[1]	1.92%	[1]
Expiration Date										Jan. 02, 2012		Jan. 02, 2012		Jan. 02, 2012		Jan. 02, 2012

[1] Fixes the LIBOR portion of the Company's US-dollar denominated variable rate borrowings (Note 9).