Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2017

Stockholders' Equity Note [Abstract]

Shares Repurchased Under Share Repurchase Program

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

	2017		2016		2015
Shares repurchased	10.1		10.5		3.9
Aggregate purchase price	$	434.9	$	497.0	$	235.1
Average purchase price per share	$	42.99	$	47.30	$	60.49

Common Stock Issued With The Exercise Of Stock Options

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

	2017		2016		2015
Shares issued	1.0		0.3		1.3
Proceeds from the exercise of stock options	$	39.7	$	8.4	$	30.0
Average exercise price per share	$	37.85	$	31.21	$	23.33

Shares Issued And Shares Surrendered To Satisfy Tax Withholdings In Connection With Restricted Stock And Restricted Stock Units

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 (in actual number of shares):

	2017	2016	2015
Shares issued	20,000	143,424	159,442
Shares surrendered to AutoNation to satisfy tax withholding obligations	26,514	38,906	36,712