Shareholders' Equity

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Note [Abstract]

SHAREHOLDERS’ EQUITY

A summary of shares repurchased under our stock repurchase program authorized by our Board of Directors follows:



	2018		2017		2016
Shares repurchased	2.1		10.1		10.5
Aggregate purchase price	$	100.0	$	434.9	$	497.0
Average purchase price per share	$	47.58	$	42.99	$	47.30

As of December 31, 2018, $263.7 million remained available under our stock repurchase limit most recently authorized by our Board of Directors.

Our Board of Directors authorized the retirement of 18.0 million shares of our treasury stock in November 2017, which assumed the status of authorized but unissued shares. Upon the retirement of treasury stock, it is our policy to charge the excess of the cost of the treasury stock over its par value entirely to additional paid-in capital. Any amounts exceeding additional paid-in capital are charged to retained earnings. This retirement had the effect of reducing treasury stock and issued common stock, which includes treasury stock. Our common stock, additional paid-in capital, retained earnings, and treasury stock accounts were adjusted accordingly. There was no impact to shareholders’ equity or outstanding common stock.

We have 5.0 million authorized shares of preferred stock, par value $0.01 per share, none of which are issued or outstanding. The Board of Directors has the authority to issue the preferred stock in one or more series and to establish the rights, preferences, and dividends.

A summary of shares of common stock issued in connection with the exercise of stock options follows:



	2018		2017		2016
Shares issued	0.5		1.0		0.3
Proceeds from the exercise of stock options	$	17.8	$	39.7	$	8.4
Average exercise price per share	$	35.25	$	37.85	$	31.21

The following table presents a summary of shares of common stock issued in connection with grants of restricted stock and settlement of restricted stock units (“RSUs”), as well as shares surrendered to AutoNation to satisfy tax withholding obligations in connection with the vesting of restricted stock and settlement of RSUs:



(In actual number of shares)	2018	2017	2016
Shares issued	122,661	20,000	143,424
Shares surrendered to AutoNation to satisfy tax withholding obligations	56,027	26,514	38,906