Stock-Based Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2017

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

The following table summarizes the stock-based compensation expense recognized, by award type, and the compensation expense recognized for phantom stock unit awards during thethree months ended March 31, 2017 and 2016 (amounts in thousands):

	Three months ended March 31,
	2017		2016
Stock option awards	$	231	$	193
Restricted stock awards	112		87
Restricted stock unit awards	984		897
	$	1,327	$	1,177
Phantom stock unit awards	$	100	$	118

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

The following table summarizes the assumptions used in the Black-Scholes option pricing model based on a weighted-average calculation for the options granted during thethree months ended March 31, 2017 and 2016:

	Three months ended March 31,
	2017		2016
Expected volatility	76	%	70	%
Risk-free interest rates	2.1	%	1.5	%
Expected life in years	5.86		5.70
Options granted	268,185		905,966
Grant-date fair value	$4.28		$0.80

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

The following table summarizes the number and weighted-average grant-date fair value of the restricted stock unit awards granted during the three months ended March 31, 2017 and 2016:

	Three months ended March 31,
	2017		2016
Time-based RSUs:
Time-based RSUs granted	66,728		231,834
Weighted-average grant-date fair value	$	6.33	$	1.31
Performance-based RSUs:
Performance-based RSUs granted	563,469		—
Weighted-average grant-date fair value	$	7.75	$	—