Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended
	May 08, 2017 shares	Aug. 04, 2016	Jun. 30, 2017 USD ($) shares	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) $ / shares shares	Jun. 30, 2016 USD ($)	Dec. 31, 2016 shares
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Common stock split ratio		2
Stock dividend payable percentage of common stock		100.00%
Stock dividend payable date					Sep. 01, 2016
Stock dividend record date					Aug. 15, 2016
Common Stock, Authorized | shares	600,000,000		600,000,000		600,000,000		300,000,000
Description of amendment to increase authorized capital	On May 8, 2017, the Company amended its Restated Certificate of Incorporation to increase its authorized shares of common stock to 600,000,000 from 300,000,000 at December 31, 2016.
Excess tax benefit from operating activities					$ 0.0	$ 18.2
Excess tax benefit from financing activities					0.0	18.2
Research and development expenses			$ 16.0	$ 16.1	30.1	$ 30.5
ASU 2016-09
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Excess tax benefit from operating activities					$ 11.1
Excess tax benefit per share from operating activities | $ / shares					$ 0.04
Excess tax benefit from financing activities					$ 11.1
Excess tax benefit per share from financing activities | $ / shares					$ 0.04