Share-Based Awards - SAR Activity (Details) - SAR Plan - SARs $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($) $ / shares shares
Number of SARs
Outstanding, beginning balance (in shares) | shares	3,586,475
Granted (in shares) | shares	1,208,550
Exercised (in shares) | shares	(2,539,055)
Forfeited (in shares) | shares	(213,750)
Outstanding, ending balance (in shares) | shares	2,042,220
Exercisable (in shares) | shares	112,733
Weighted average exercise price
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 9.16
Granted (in dollars per share) | $ / shares	35.60
Exercised (in dollars per share) | $ / shares	6.90
Forfeited (in dollars per share) | $ / shares	25.27
Outstanding, ending balance (in dollars per share) | $ / shares	25.93
Exercisable (in dollars per share) | $ / shares	$ 10.29
Outstanding, Weighted average remaining contractual life	8 years 3 months 18 days
Exercisable, Weighted average remaining contractual life	5 years 7 months 6 days
Outstanding, Aggregate intrinsic value | $	$ 16,316
Exercisable, Aggregate intrinsic value | $	$ 2,858