Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2015

Stockholders' Equity

Summary of share repurchases

The table below summarizes the Company's share repurchases beginning January 1, 2013 under its Board of Directors' authorizations:

		Amount Authorized by Board (Shares in millions)				Shares Remaining Under Board Authorization (millions)		Shares Repurchased Under Board Authorization
				Total Shares Repurchased (millions)
	Expiration Date
Repurchase Program Authorization Date								2015		2014		2013
October 2011	none		4.0		4.0		—		—		—		1.5
May 2013	none		4.0		4.0		—		0.8		2.7		0.5
October 2014	none		4.0		1.2		2.8		1.2		—		—
Total shares repurchased under authorization									2.0		2.7		2.0
Cost (millions)								$	42.0	$	48.2	$	28.2
Average share price								$	21.10	$	18.03	$	14.05