FINANCIAL INSTRUMENTS

Investments

The Corporation's investments in marketable securities are classified as available-for-sale.



Investing Results
In millions	2012		2011		2010
Proceeds from sales of available-for-sale securities	$	—	$	9	$	25

Portfolio managers regularly review all of the Corporation's holdings to determine if any investments are other-than-temporarily impaired. The analysis includes reviewing the amount of the impairment, as well as the length of time it has been impaired. In addition, specific guidelines for each instrument type are followed to determine if an other-than-temporary impairment has occurred. At December 31, 2012 and December 31, 2011, there were no impairment indicators or circumstances that would result in a material adjustment of these investments.

The Corporation's investments in debt securities had contractual maturities of less than 10 years at December 31, 2012.



Fair Value of Financial Instruments:
	At December 31, 2012											At December 31, 2011
In millions	Cost			Gain		Loss			Fair Value			Cost			Gain		Loss			Fair Value
Marketable securities (1):
Debt securities	$	5		$	—	$	—		$	5		$	3		$	—	$	—		$	3
Total marketable securities	$	5		$	—	$	—		$	5		$	3		$	—	$	—		$	3
Long-term debt	$	(471	)	$	—	$	(116	)	$	(587	)	$	(507	)	$	—	$	(148	)	$	(655	)


(1)	Included in “Other investments” in the consolidated balance sheets.

Cost approximates fair value for all other financial instruments.