Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Fair Value, by Balance Sheet Grouping

The estimated fair values of our other financial instruments at December 31, 2012 and 2011 have been calculated based upon available market information or an appropriate valuation technique, and are as follows:

	December 31, 2012				December 31, 2011
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Level 1:
Subordinated convertible debentures	$	55	$	63	$	55	$	49
Senior and senior subordinated notes	5,387		5,881		1,732		1,795
Level 2:
4 percent Convertible Senior Notes (1)	137		155		129		138
Level 3:
Capital leases (2)	148		145		39		33

(1) The fair value of the 4 percent Convertible Senior Notes is based on the market value of comparable notes. Consistent with the carrying amount, the fair value excludes the equity component of the notes. To exclude the equity component and calculate the fair value, we used an effective interest rate of 6.9 percent.

(2) The fair value of capital leases reflects the present value of the leases using a 7.0 percent interest rate.