Shareholders' Equity

3 Months Ended

Mar. 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:



	Three Months Ended
	March 31,
	2018		2017
Shares repurchased	0.5		—
Aggregate purchase price	$	26.6	$	—
Average purchase price per share	$	48.38	$	—

As of March 31, 2018, $87.1 million remained available for share repurchases under the program. In April 2018, our Board of Directors authorized the repurchase of an additional $250 million of shares of our common stock.

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



	Three Months Ended
	March 31,
	2018		2017
Shares issued	0.3		0.6
Proceeds from the exercise of stock options	$	13.3	$	21.5
Average exercise price per share	$	51.15	$	34.03

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):



	Three Months Ended
	March 31,
	2018	2017
Shares issued	112,824	—
Shares surrendered to AutoNation to satisfy tax withholding obligations	45,690	8,124