Stock-Based Compensation Plans (Stock Option Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Shares
Closing Balance (in shares)	12,814,365
Options outstanding - end of the year (in shares)	7,027,974
Per share weighted average exercise prices
Closing Balance (in dollars per shares)	$ 11.81
Options exercisable - end of the year (in dollars per share)	$ 16.76
Stock Options
Shares
Closing Balance (in shares)	12,822,684	13,593,156
Granted (in shares)	2,801,982	869,297
Exercised (in shares)	(33,501)	0	0
Canceled (in shares)	(1,653,126)	(533,921)
Expired (in shares)	(1,123,674)	(1,105,848)
Closing Balance (in shares)	12,814,365	12,822,684	13,593,156
Options outstanding - end of the year (in shares)	7,027,974	7,288,614
Per share weighted average exercise prices
Opening Balance (in dollars per shares)	$ 14.08	$ 15.30
Exercised (in period)	6.82	0
Granted (in dollars per share)	3.98	6.57
Canceled (in dollars per share)	10.09	11.06
Expired (in dollars per share)	22.09	24.75
Closing Balance (in dollars per shares)	11.81	14.08	$ 15.30
Options exercisable - end of the year (in dollars per share)	$ 16.76	$ 18.49