Equity Incentive Plans (Nonvested Stock Option Activity) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of the activity of stock option awards, shares
Options outstanding, beginning balance, shares	590
Granted, shares	462	300	300
Vested, shares	(262)
Forfeited, shares	(83)
Options outstanding, ending balance, shares	707	590
Options non vested, Wtd. avg. grant date fair value beginning balance (in dollars per share)	$ 1.93
Granted, Wtd. Avg. grant date fair value (in dollars per share)	5.91	$ 2.09	$ 4.26
Vested, Wtd. Avg. grant date fair value (in dollars per share)	2.01
Forfeited, Wtd. Avg. grant date fair value (in dollars per share)	3.87
Options non vested, Wtd. avg. grant date fair value ending balance (in dollars per share)	$ 3.93	$ 1.93
Stock Options
Summary of the activity of stock option awards, shares
Unrecognized compensation costs related to awards	$ 2.0
Expected weighted average period to recognize expense	2 years 10 months 24 days