Share-Based Compensation Plans Stock Options (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Shares Outstanding beginning balance | shares	3,727
Number of shares granted | shares	415
Number of shares exercised | shares	(533)
Number of shares forfeited or expired | shares	(274)
Number of shares outstanding ending balance | shares	3,335
Number of shares fully vested and expected to vest | shares	3,304
Number of shares exercisable | shares	2,337
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share outstanding beginning balance | $ / shares	$ 6.49
Weighted average exercise price per share granted | $ / shares	5.73
Weighted average exercise price per share exercised | $ / shares	4.88
Weighted average exercise price per share forfeited or expired | $ / shares	6.63
Weighted average exercise price per share outstanding ending balance | $ / shares	6.65
Weighted average exercise price per share fully vested and expected to vest | $ / shares	6.65
Weighted average exercise price per share exercisable | $ / shares	$ 7.05
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term outstanding (years)	6 years 22 days
Weighted average remaining contractual term fully vested and expected to vest (years)	6 years 11 days
Weighted average remaining contractual term exercisable (years)	5 years 22 days
Aggregate intrinsic value outstanding ending balance (in dollars) | $	$ 11,051
Aggregate intrinsic value fully vested and expected to vest (in dollars) | $	10,938
Aggregate intrinsic value exercisable (in dollars) | $	$ 7,020