Shareholders' Equity (Phantom Share Units) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value Assumptions
Current accrued liabilities	$ 4,427		$ 4,427		$ 3,129
Stock-based compensation	$ 1,234	$ 1,064	$ 3,581	$ 2,978
Phantom Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years
Number of Phantom Share Units (000's)
Beginning balance (in shares)			1,350
Issued (in shares)			346
Vested (in shares)			(601)
Expired / Forfeited (in shares)			(76)
Ending balance (in shares)	1,019		1,019
Fair Value Assumptions
Share price (USD per share)	$ 8.64		$ 8.64
Calculated fair value of phantom share units			$ 5,159
Total liability	$ 5,159		5,159
Current accrued liabilities	4,427		4,427
Long-term accrued liabilities	732		732
Cash settlement			4,201	3,386
Phantom Share Units | Selling, general, and administrative
Fair Value Assumptions
Stock-based compensation	$ 459	$ 1,054	$ 4,070	$ 5,654
Phantom Share Units | Minimum
Fair Value Assumptions
Remaining life of phantom share units			7 months 9 days
Phantom Share Units | Maximum
Fair Value Assumptions
Remaining life of phantom share units			2 years 7 months 9 days