Earnings (Loss) Per Common Share (EPS) - Diluted EPS (Details) - $ / shares shares in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share, Basic and Diluted [Abstract]
Average common shares outstanding (in shares)									55,434	55,075	52,268
Effect of dilutive stock options (in shares)										1,160	1,663
Total potential shares outstanding (in shares)									55,434	56,235	53,931
Diluted EPS (in dollars per share)	$ 0.27	$ (0.05)	$ (0.34)	$ (0.06)	$ (0.08)	$ (0.06)	$ 0.12	$ 0.11	$ (0.18)	$ 0.10	$ 0.78
Equity awards excluded as the impact was anti-dilutive (in shares)									4,216	1,750	396