Stock-Based Awards (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		12 Months Ended
	Jan. 01, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Sep. 15, 2015
Stock-based awards
Options granted (in shares)		68,500
Number of Shares
Number of Shares, beginning balance	1,738,524	1,738,524
Number of Shares, Granted		68,500
Number of Shares, ending balance		1,807,024		1,738,524
Number of Shares, Options vested and expected to vest		1,807,024
Number of Shares, Options exercisable		180,422
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in dollars per share)	$ 13.23	$ 13.23
Weighted Average Exercise Price, Granted (in dollars per share)		20.28
Weighted Average Exercise Price, ending balance (in dollars per share)		13.50		$ 13.23
Weighted Average Exercise Price, Options vested and expected to vest (in dollars per share)		13.50
Weighted Average Exercise Price, Options exercisable (in dollars per share)		$ 1.27
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term (in years)		9 years 3 months 11 days		9 years 6 months 4 days
Weighted Average Remaining Contractual Term, Options vested and expected to vest (in years)		9 years 3 months 11 days
Weighted Average Remaining Contractual Term, Options exercisable (in years)		8 years 5 months 27 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value		$ 14,892		$ 24,722
Aggregate Intrinsic Value, Options vested and expected to vest		14,892
Aggregate Intrinsic Value, Options exercisable		$ 3,189
Weighted average grant-date fair value of stock options granted (in dollars per share)		$ 16.75
Employee, director and consultant stock options
Stock Option Valuation
Risk-free interest rate (as a percent)		1.49%
Expected term (in years)		7 years 3 months 18 days
Expected volatility (as a percent)		99.97%
Expected dividend yield (as a percent)		0.00%
Expected forfeiture rate (as a percent)		0.00%	0.00%
2012 Equity Compensation Plan
Stock-based awards
Number of shares available for grant		0
Number of Shares
Number of Shares, beginning balance	1,140,524	1,140,524
Number of Shares, ending balance		1,140,524		1,140,524
2012 Equity Compensation Plan | Employee, director and consultant stock options
Stock-based awards
Term of award (in years)		10 years
Vesting period (in years)		4 years
2015 Equity Incentive Plan
Stock-based awards
Number of shares available for grant		2,856,695
Number of shares authorized					2,784,395
Percentage increase to shares available for grant from common outstanding as of preceding December 31 (as a percent)					4.00%
Additional shares available	806,300