Stock Options, Restricted Stock and Employee Stock Purchase Plan - Stock Option Activity (Details) - Stock Option Plan 2014 And 2003 - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Beginning balance, outstanding (in Shares)	4,053	4,766	4,762
Granted (in Shares)	0	66	2,089
Exercised (in Shares)	(22)	(623)	(1,794)
Forfeited or expired (in Shares)	(613)	(156)	(291)
Ending balance, outstanding (in Shares)	3,418	4,053	4,766
Number of Shares, Exercisable (in Shares)	2,350
Weighted Average Exercise Price
Beginning balance, outstanding (in Dollars per share)	$ 28.95	$ 27.27	$ 20.33
Granted (in Dollars per share)	0.00	21.28	26.61
Exercised (in Dollars per share)	24.99	15.53	7.78
Forfeited or expired (in Dollars per share)	31.28	28.20	28.96
Ending balance, outstanding (in Dollars per share)	28.55	$ 28.95	$ 27.27
Weighted Average Exercise Price, Exercisable (in Dollars per share)	$ 29.00
Weighted Average Remaining Contractual Term (Years)	3 years 8 months 10 days
Weighted Average Remaining Contractual Term, Exercisable (Years)	3 years 4 months 28 days
Aggregate Intrinsic Value	$ 0
Aggregate Intrinsic Value, Exercisable	$ 0