Stock-Based Compensation (Stock Option and SSARs Activity) (Details) - Stock options $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($) $ / shares shares
Number Outstanding [Roll Forward]
Outstanding at December 31, 2017 \| shares	4,272,651
Granted \| shares	769,477
Exercised \| shares	(825,186)
Forfeited \| shares	(91,875)
Outstanding at December 31, 2018 \| shares	4,125,067
Weighted Average Exercise Price [Roll Forward]
Outstanding at December 31, 2017 \| $ / shares	$ 8.68
Granted \| $ / shares	12.82
Exercised \| $ / shares	8.22
Forfeited \| $ / shares	12.19
Outstanding at December 31, 2018 \| $ / shares	$ 9.46
Outstanding at December 31, 2017, Weighted Average Remaining Contractual Term	3 years 3 months 3 days
Outstanding at December 31, 2017, Aggregate Intrinsic Value \| $	$ 0.5
Exercisable shares at December 31, 2017 \| shares	2,942,466
Exercisable shares at December 31, 2017, Weighted Average Exercise Price \| $ / shares	$ 8.12
Exercisable shares at December 31, 2017, Weighted Average Contractual Term	2 years 2 months 27 days
Exercisable shares at December 31, 2017, Aggregate Intrinsic Value \| $	$ 0.5

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.