Income (Loss) Per Share - Weighted Average Number of Shares (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Shares used to calculate basic income (loss) per share (in shares)	30,038	29,728	29,914	29,660
Dilutive effect of outstanding stock options, performance stock units and restricted stock units (in shares)	2,363	0	1,878	0
Shares used to calculate diluted income (loss) per share (in shares)	32,401	29,728	31,792	29,660