Shareholders' Equity

9 Months Ended

Sep. 30, 2017

Stockholders' Equity Note [Abstract]

SHAREHOLDERS’ EQUITY

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



	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2017		2016		2017		2016
Shares repurchased	9.2		1.0		10.1		9.9
Aggregate purchase price	$	400.0	$	50.0	$	434.9	$	470.6
Average purchase price per share	$	43.28	$	48.62	$	42.99	$	47.48

In August 2017, our Board of Directors authorized the repurchase of an additional $250 million of shares of our common stock. As of September 30, 2017, $113.7 million remained available for share repurchases under the program.

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



	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2017		2016		2017		2016
Shares issued	0.1		0.1		0.7		0.3
Proceeds from the exercise of stock options	$	1.9	$	4.6	$	24.7	$	7.8
Average exercise price per share	$	35.27	$	35.55	$	33.77	$	30.93

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):



	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2017	2016	2017	2016
Shares issued	—	—	20,000	152,683
Shares surrendered to AutoNation to satisfy tax withholding obligations	141	4,788	26,061	37,673