Income (Loss) Per Common Share - Shares Excluded from EPS (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Common share equivalents
Diluted income (loss) per share
Securities excluded from the diluted calculation as their effect would be antidilutive	403	16	302	17
Potentially dilutive shares
Diluted income (loss) per share
Securities excluded from the diluted calculation as their effect would be antidilutive	1,874	2,617	1,893	2,469
Convertible Notes
Diluted income (loss) per share
Securities excluded from the diluted calculation as their effect would be antidilutive	8,618	8,618	8,618	8,618