Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2017

The following table summarizes stock option activity for the years ended December 31, 2017, 2016 and 2015 (shares and intrinsic values in thousands):

	Number of shares			Weighted- average exercise price		Weighted- average remaining contractual term		Aggregate intrinsic value
Outstanding at December 31, 2014		1,870		$	11.23		8.4	$	4,721
Granted		215		$	13.61		6.2		—
Exercised		(15	)		10.60		—		—
Forfeited or expired		(27	)		10.60		—		—

Outstanding at December 31, 2015		2,043		$	11.49		7.6	$	6,740
Granted		890		$	11.97		6.2		—
Exercised		(13	)		10.60		—		—
Forfeited or expired		—			—		—		—

Outstanding at December 31, 2016		2,920		$	11.64		7.6	$	1,274


Granted		55		$	11.35		6.0		—
Exercised		—			—		—		—
Forfeited		(37	)		10.39		—		—
Expired		(40	)	$	11.51		—		—

Outstanding at December 31, 2017		2,898		$	11.62		6.5	$	1,738


Vested at December 31, 2017		1,888		$	11.69		5.8	$	1,322


Exercisable at December 31, 2017		1,888		$	11.69		5.8	$	1,322

The following table summarizes restricted share activity for the years ended December 31, 2017, 2016 and 2015 (shares in thousands):

	Number of shares			Weighted-average grant date fair value
Outstanding at December 31, 2014		719		$	9.82
Granted		99			12.42
Vested		(324	)		10.65
Forfeited		—			—

Outstanding at December 31, 2015		494		$	9.79
Granted		395			11.82
Vested		(328	)		10.88
Forfeited		—			—

Outstanding at December 31, 2016		561		$	10.58
Granted		154			11.19
Vested		(203	)		11.80
Forfeited		(8	)		13.38

Outstanding at December 31, 2017		504		$	10.23

Black-Scholes Option Valuation Assumptions	2017			2016	2015
Risk-free interest rate		2.18	%	1.60% - 2.44%	1.76% - 2.12%
Dividend yield		—		—	—
Volatility		25.8	%	26.4% - 32.4%	25.8% - 29.5%
Weighted-average expected term (years)		6.0		6.2	6.3