Stock-based Compensation - Stock Option Exercise Price (Details)	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Stock options exercisable and vested
Number of Shares	3,309,158
Weighted-Average Remaining Life	4 years
$20.00
Stock options exercisable and vested by exercise price range
Exercise price (in dollars per share) | $ / shares	$ 20.00
Stock options exercisable and vested
Number of Shares	3,159,158
Weighted-Average Remaining Life	3 years 11 months 16 days
$28.80
Stock options exercisable and vested by exercise price range
Exercise price (in dollars per share) | $ / shares	$ 28.80
Stock options exercisable and vested
Number of Shares	150,000
Weighted-Average Remaining Life	4 years 9 months 26 days