Stock-Based Compensation - Performance Stock Units (Details) - USD ($)		1 Months Ended	12 Months Ended
	May 10, 2018	May 30, 2018	Apr. 01, 2018	Mar. 26, 2017	Mar. 27, 2016
Stock-based compensation
Number of fiscal years over which stock option grants have been made to senior management			2 years
Performance Stock Units
Stock-based compensation
Measurement period			1 year
PSU Activity
Unvested shares available for issue under outstanding PSUs, beginning of period (in shares)			170,100	138,925	203,841
Granted (in shares)			86,000	207,000	103,000
Vested (in shares)			(7,600)	(27,671)	(87,648)
Forfeited/cancelled (in shares)			(181,500)	(148,154)	(80,268)
Unvested shares available for issue under outstanding PSUs, end of period (in shares)			67,000	170,100	138,925
Unvested PSUs, Weighted-Average Fair Value at Grant Date
Unvested shares available for issue under outstanding PSUs, beginning of period (in dollars per share)			$ 11.17	$ 21.46	$ 20.65
Granted (in dollars per share)			12.67	10.77	22.15
Vested (in dollars per share)			19.58	19.40	13.88
Forfeited/cancelled (in dollars per share)			10.99	18.72	28.57
Unvested shares available for issue under outstanding PSUs, end of period (in dollars per share)			$ 12.65	$ 11.17	$ 21.46
Additional stock based compensation information
Unrecognized compensation costs (in dollars)			$ 300,000
Total fair value of shares vested during period (in dollars)			$ 277,600	$ 628,200	$ 2,543,000
Shares earned, but not yet vested (in shares)			50,250
Performance Stock Units | Subsequent Event
PSU Activity
Forfeited/cancelled (in shares)	(16,750)
Additional stock based compensation information
Canceled shares, performance targets not fully satisfied (in shares)		16,750
Award Date, May 10, 2018 | Performance Stock Units | Subsequent Event
Stock-based compensation
Measurement period	1 year
PSU Activity
Granted (in shares)	71,000
Additional stock based compensation information
Annual vesting percentage	25.00%