Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Fair value of financial instruments

The estimated fair values of our financial instruments as of June 30, 2015 and December 31, 2014 have been calculated based upon available market information, and are presented below by level in the fair value hierarchy:

	June 30, 2015				December 31, 2014
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Level 1:
Senior and senior subordinated notes	$	5,991	$	6,090	$	6,063	$	6,390
Level 2:
4 percent Convertible Senior Notes (1)	7		8		32		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. As discussed below (see Item 3- Quantitative and Qualitative Disclosures about Market Risk), the total cost to settle the notes based on the closing price of our common stock on June 30, 2015 would be $60.