Employee Stock and Benefit Plans (Stock Option Exchange) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions			12 Months Ended
	Dec. 06, 2016	Nov. 03, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional compensation cost to be recognized			$ 3.4
Additional compensation cost, expected recognition period			3 years 4 months 24 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of options granted (in dollars per share)			$ 3.17	$ 4.29	$ 4.50
Options granted			2,339	993	1,230
Stock Option Exchange Program | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum exercise price to qualify for program (in dollars per share)		$ 4.33
Exercise price of options granted (in dollars per share)	$ 4.73
Options granted			2,000
Options granted, percentage of eligible shares outstanding			58.00%
Additional compensation cost to be recognized			$ 1.5
Additional compensation cost, expected recognition period			2 years