Long-term Equity-based Compensation - Option and SAR Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Shares Subject to Awards
Outstanding at Beginning of the Year (in shares) | shares	1,434,273
Granted (in shares) | shares	578,375
Exercised (in shares) | shares	(159,630)
Forfeited or Expired (in shares) | shares	(44,203)
Outstanding at December 31, 2019 (in shares) | shares	1,808,815
Vested and Expected to Vest at December 31, 2019 (in shares) | shares	1,718,559
Exercisable at December 31, 2019 (in shares) | shares	803,769
Weighted- average Exercise Price Per Share ($)
Outstanding at Beginning of the Year (in dollars per share) | $ / shares	$ 46.48
Granted (in dollars per share) | $ / shares	76.96
Exercised (in dollars per share) | $ / shares	36.92
Forfeited or Expired (in dollars per share) | $ / shares	68.43
Outstanding at December 31, 2019 (in dollars per share) | $ / shares	56.53
Vested and Expected to Vest at December 31, 2019 (in dollars per share) | $ / shares	56.03
Exercisable at December 31, 2019 (in dollars per share) | $ / shares	$ 42.15
Weighted- average Remaining Contractual Life (in Years)
Outstanding at December 31, 2019	7 years 7 months 24 days
Vested and Expected to Vest at December 31, 2019	7 years 7 months 9 days
Exercisable at December 31, 2019	6 years 6 months
Aggregate Intrinsic Value ($ In Millions)
Outstanding at December 31, 2019 | $	$ 38.3
Vested and Expected to Vest at December 31, 2019 | $	37.2
Exercisable at December 31, 2019 | $	$ 28.4