Common Stock and Stockholders' Equity - Additional Information (Details) $ / shares in Units, $ in Millions				12 Months Ended
	Jan. 01, 2018 shares	Jan. 01, 2017 shares	May 06, 2016 shares	Dec. 31, 2017 USD ($) offering_period $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)				400,000,000	400,000,000
Common stock, par value (usd per share) | $ / shares				$ 0.01	$ 0.01
Common stock, shares issued (in shares)				103,100,000	97,200,000
Common stock, shares outstanding (in shares)				103,100,000	96,700,000
Common stock, shares repurchased (in shares)				3,000	100,000
Preferred stock, shares authorized (in shares)				10,000,000	10,000,000
Preferred stock, par value (usd per share) | $ / shares				$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)				0	0
Preferred stock, shares outstanding (in shares)				0	0
Common shares purchased (in shares)				700,000	600,000
Increase in authorized shares (in shares)				4,833,000
Shares of common stock available for issuance (in shares)				8,001,000	6,039,000
Stock options granted (in shares)			1,200,000	1,203,000
Intrinsic value of options exercised | $				$ 47.1	$ 49.2	$ 66.2
Vesting period				4 years
Weighted-average grant date fair value of stock options (usd per share) | $ / shares				$ 13.07	$ 11.34	$ 12.44
Employee Stock Option
Class Of Stock [Line Items]
ESPP offering period				18 months
Number of offering periods | offering_period				3
Length of purchase period				6 months
Share based compensation related to accelerated vesting | $				$ 1.5	$ 0.7	$ 0.0
2009 Stock Option and Grant Plan
Class Of Stock [Line Items]
Shares of common stock available for issuance (in shares)				0
2014 Plan | Employee Stock Option
Class Of Stock [Line Items]
Increase in authorized shares (in shares)		4,800,000.0
Shares of common stock available for issuance (in shares)				8,000,000
Subsequent Event | 2014 Plan | Employee Stock Option
Class Of Stock [Line Items]
Increase in authorized shares (in shares)	5,200,000.0
Employee Stock Purchase Plan
Class Of Stock [Line Items]
Percentage of purchase price of shares lower of the fair market value of common stock employees are able to purchase shares				85.00%
Increase in authorized shares (in shares)		1,000,000
Shares of common stock available for issuance (in shares)				3,600,000
Employee Stock Purchase Plan | Subsequent Event
Class Of Stock [Line Items]
Increase in authorized shares (in shares)	1,000,000