Stock Options, Restricted Stock and Employee Stock Purchase Plan (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The assumptions used in estimating the fair value of the stock options granted during the period, along with the weighted-average grant date fair values, were as follows:

	2017			2016
Expected volatility	50%	—	50%	46%	—	50%
Expected life (in years)		4.8			4.7
Risk-free interest rate	1.7%	—	1.7%	0.9%	—	1.8%
Dividend yield		—			—
Weighted-average grant date fair value per stock option		$9.25			$11.13

Schedule of Share-based Compensation, Activity

summary of stock option activity within the Company’s stock-based compensation plans for the years ended December 31, 2018, 2017 and 2016:

	Number of Shares (in thousands)		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (in thousands) (1)
Outstanding at December 31, 2015	4,762		$	20.33
Granted	2,089		26.61
Exercised	(1,794	)	7.78
Forfeited or expired	(291	)	28.96
Outstanding at December 31, 2016	4,766		$	27.27
Granted	66		21.28
Exercised	(623	)	15.53
Forfeited or expired	(156	)	28.20
Outstanding at December 31, 2017	4,053		$	28.95
Granted	—		—
Exercised	(22	)	24.99
Forfeited or expired	(613	)	31.28
Outstanding at December 31, 2018	3,418		$	28.55	3.69	$	—
Exercisable at December 31, 2018	2,350		$	29.00	3.41	$	—

(1) Includes only those options that were in-the-money as of December 31, 2018. Fluctuations in the intrinsic value of both outstanding and exercisable options may result from changes in underlying stock price and the timing and volume of option grants, exercises and forfeitures.

Schedule of Nonvested Restricted Stock Units Activity

:

	Number of Shares (in thousands)		Weighted Average Per Share Grant Date Fair Value
Unvested at December 31, 2015	253		$	35.31
Granted	303		29.50
Vested	(118	)	34.95
Forfeited	(22	)	28.85
Unvested at December 31, 2016	416		$	31.52
Granted	666		33.10
Vested	(137	)	32.55
Forfeited	(57	)	31.34
Unvested at December 31, 2017	888		$	32.55
Granted (1)	1,711		16.07
Vested	(408	)	30.22
Forfeited (1)	(548	)	24.00
Unvested at December 31, 2018	1,643		$	19.85

(1) RSUs granted and forfeited include 0.4 million RSUs held by the Company’s former CEO and COO that were modified to accelerate vesting. This modification was treated as forfeiture of the old awards and granting of new awards with modified vesting terms.