Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Share-Based Compensation Expense By Type [Table Text Block]

Share-based compensation expense (income) was as follows:

	Year Ended December 31,
	2020		2019		2018
PUs	$	916	$	277	$	(3,925)
RSUs	6,994		8,432		9,241
Stock options	2,525		3,156		3,204
Total	$	10,435	$	11,865	$	8,520

Schedule of Share-based Compensation, Stock Options, Activity

Stock option transactions and related information for the year ended December 31, 2020 was as follows:

	Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding as of January 1, 2020	548,770	$	77.68
Granted	233,732	$	25.19
Exercised	—	$	—
Forfeited	(21,757)	$	49.53
Expired	(19,326)	$	51.62
Outstanding as of December 31, 2020	741,419	$	62.64	6.1	$	2,103
Exercisable as of December 31, 2020	408,316	$	78.37	5.0	$	—

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

The fair value of each option was estimated using the following assumptions:

	2020		2019		2018
Expected volatility	33.74%		29.48% - 31.10%		27.17% - 27.19%
Dividend yield	0.00	%	0.00	%	0.00	%
Expected option life - years	6.0		6.0		6.0
Risk-free rate	1.5%		1.8% - 2.5%		2.6%

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

Restricted stock and restricted stock units transactions and related information for the year ended December 31, 2020 was as follows:

	Restricted Stock and Restricted Units	Weighted Average Grant Date Fair Value
Non-vested as of January 1, 2020	332,981	$	83.60
Granted	169,038	$	17.62
Vested	(86,976)	$	99.41
Forfeited	(29,408)	$	73.75
Non-vested as of December 31, 2020	385,635	$	54.10

Schedule of Nonvested Performance-based Units Activity [Table Text Block]

A summary of activity for performance-vested restricted stock units transactions and related information for the year ended December 31, 2020 was as follows:

	Performance Units	Weighted Average Grant Date Fair Value
Non-vested as of January 1, 2020	194,053	$	93.86
Granted	130,346	$	10.10
Vested	(48,772)	$	107.50
Forfeited	(17,387)	$	57.57
Non-vested as of December 31, 2020	258,240	$	51.45

Schedule of Share-based Payment Award, TSRs, Valuation Assumptions [Table Text Block]

The fair value of the performance units granted in 2020 was estimated using the following assumptions:

	2020
Expected volatility	116.60	%
Dividend yield	0.00	%
Risk-free rate	0.10	%