Stock-Based Compensation Non-Qualified Stock Options Activity (Details) - NSO	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning of period (shares) | shares	2,846,926
Granted (shares) | shares	201,580
Exercised (shares) | shares	(20,643)
Forfeitures (shares) | shares	(7,224)
Cancelled (shares) | shares	(494,069)
Outstanding, end of period (shares) | shares	2,526,570
Vested and exercisable, shares end of period (shares) | shares	1,200,643
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period, weighted average exercise price (usd per share) | $ / shares	$ 39.00
Granted, weighted average exercise price (usd per share) | $ / shares	42.85
Exercised, weighted average exercise price (usd per share) | $ / shares	28.14
Forfeitures, weighted average exercise price (usd per share) | $ / shares	30.66
Cancellations, weighted average exercise price (usd per share) | $ / shares	54.57
Outstanding, end of period, weighted average exercise price (usd per share) | $ / shares	36.37
Vested and exercisable, weighted average exercise price, end of period (usd per share) | $ / shares	$ 40.48