Stock Options, Restricted Stock Units and Employee Stock Purchase Plan - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Number of Options
Granted (in Shares)	0
Exercised (in Shares)	(400,000)	(1,500,000)	(500,000)	(1,500,000)
2014 and 2003 Stock Option Plan
Number of Options
Options outstanding, beginning balance (in Shares)			4,766,000
Granted (in Shares)			66,000
Exercised (in Shares)			(457,000)
Forfeited (in Shares)			(112,000)
Options outstanding, ending balance (in Shares)	4,263,000		4,263,000		4,766,000
Options, exercisable (in Shares)	1,549,000		1,549,000
Weighted Average Exercise Price
Weighted average exercise price, beginning balance (in Dollars per share)			$ 27.27
Granted (in Dollars per share)			21.28
Exercised (in Dollars per share)			15.44
Forfeited (in Dollars per share)			27.27
Weighted average exercise price, ending balance (in Dollars per share)	$ 28.45		28.45		$ 27.27
Weighted average exercise price, exercisable (in Dollars per share)	$ 27.57		$ 27.57
Weighted Average Remaining Contractual Term			4 years 10 months 28 days		5 years 11 days
Weighted Average Remaining Contractual Term, exercisable			3 years 7 months 20 days
Aggregate Intrinsic Value	$ 28,735		$ 28,735		$ 5,714
Aggregate Intrinsic Value, exercisable	$ 12,706		$ 12,706