Note 9 — Capital Stock

Common Stock Outstanding

Common stock outstanding as of December 31, 2017, 2016 and 2015 was as follows:

(Number of shares in millions)	2017		2016		2015
Common stock:
Balance, beginning of year	106.7			106.0	104.8
Activity under stock plans	1.1		0.7		1.2
Balance, end of year	107.8		106.7			106.0
Treasury stock:
Balance, beginning of year	15.3		12.5		9.3
Repurchased		2.9	2.8		3.2
Balance, end of year	18.2		15.3		12.5
Common stock outstanding	89.6		91.4		93.5

In June 2014, our Board authorized a plan to repurchase $150 million of our outstanding common stock (“2014 Repurchase Plan”). In October 2015, our Board authorized the repurchase of $250 million of the Company’s common stock. During February of 2017, the Board authorized the repurchase on an additional $300 million of the Company’s common stock of which $242.5 million is still available at December 31, 2017. During 2017, 2016 and 2015, the Company spent $150.3 million, $111.1 million, and $146.1 million to repurchase common stock under its repurchase programs.

During 2017 the Company paid $42.6 million in dividends on its common stock. Dividends per share of common stock for 2017, 2016, and 2015, were $0.47, $0.44, and $0.40, respectively.