Stock Options, Restricted Stock and Employee Stock Purchase Plan - Narrative (Details)	1 Months Ended	12 Months Ended
	Jan. 31, 2018 shares	Dec. 31, 2018 USD ($) offering_period shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares	Dec. 16, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense | $		$ 21,500,000	$ 21,000,000	$ 15,400,000
Share-based compensation expense due to accelerated vesting | $		2,100,000
Total intrinsic value of stock options exercised | $		200,000	9,800,000	40,300,000
Additional paid-in-capital recorded | $		500,000	$ 9,700,000	$ 14,000,000
Total unrecognized compensation cost | $		$ 7,000,000
Recognition period for unrecognized compensation cost		1 year 3 months 25 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs granted (in Shares)		1,711,000	666,000	303,000
Vested (in Shares)		408,000	137,000	118,000
Forfeited (in Shares)		548,000	57,000	22,000
Total unrecognized compensation cost | $		$ 25,400,000
Recognition period for unrecognized compensation cost		2 years 9 months 55 days
Vesting rights, percentage		25.00%
Vesting period		4 years
Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in Shares)		8,000,000.0
Number of shares granted (in Shares)		0
Number of shares remaining available for issuance (in Shares)		6,200,000
Omnibus Plan | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs outstanding (in Shares)		1,500,000
Number of RSUs granted (in Shares)		2,000,000
Vested (in Shares)		300,000
Forfeited (in Shares)		200,000
2014 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in Shares)					7,500,000
Number of shares outstanding (in Shares)		3,400,000
2014 Plan | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs outstanding (in Shares)		100,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in Shares)		2,000,000
Share-based compensation expense | $		$ 1,100,000
Discount from market price at the beginning or end of the offering period		15.00%
Number of offering periods | offering_period		2
Maximum annual purchases per employee under ESPP | $		$ 25,000
Maximum annual withholdings per employee for purchases under ESPP | $		$ 21,250
Maximum number of shares available for purchase per employee (in Shares)		15,000
Cash contributions to ESPP | $		$ 2,800,000
Shares issued under plan (in Shares)	100,000
Remaining number of shares authorized under ESPP (in shares)		1,900,000
ESPP | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of base wages withheld for purchase of stock		1.00%
ESPP | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of base wages withheld for purchase of stock		15.00%