EQUITY

12 Months Ended

Dec. 31, 2011

EQUITY

EQUITY

17. EQUITY

        Changes in common shares and treasury stock were as follows:

(In millions)	Common Shares Issued		Treasury Stock		Cost of Treasury Stock
Balance—January 1, 2009		—		—	$	—
IPO		204.5		—		—
Balance—December 31, 2009		204.5		—		—
Stock-based compensation		0.3		0.1		3.1
Treasury stock purchases		—		—		0.1
Balance—December 31, 2010		204.8		0.1	$	3.2
Stock-based compensation		0.3		—		4.9
Treasury stock purchases		—		1.3		81.6
Balance—December 31, 2011		205.1		1.4	$	89.7

        Treasury stock is recognized at the cost to reacquire the shares. Shares issued from treasury are recognized using the first-in first-out method.