Common Stockholders' Equity

12 Months Ended

Dec. 31, 2015

Equity [Abstract]

Common Stockholders' Equity

Common Stockholders’ Equity

The weighted average number of shares used in the computation of net income per share was as follows:

	2015	2014	2013
Basic	124,040,313	127,873,708	135,304,752
Diluted	130,188,866	133,651,855	140,742,922

Treasury shares have been excluded from average outstanding shares from the date of acquisition. The difference in calculating basic and diluted net income per share is attributable entirely to the dilutive effect of stock-based compensation plans.

Changes in shares of common stock outstanding, net of treasury shares, are presented below. Shares of common stock issued and outstanding do not include shares related to unissued restricted stock units and unexercised stock options.

	2015		2014		2013
Balance, beginning of year	126,748,836		132,233,167		136,017,732
Shares issued	1,061,026		332,137		139,790
Shares repurchased	(4,502,025	)	(5,816,468	)	(3,924,355)
Balance, end of year	123,307,837		126,748,836		132,233,167

The amount of dividends paid is dependent upon factors such as the receipt of dividends from our subsidiaries, our results of operations, cash flow, financial condition and business needs, the capital and surplus requirements of our subsidiaries, and applicable insurance regulations that limit the amount of dividends that may be paid by our regulated insurance subsidiaries.