Net income (loss) per common share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 01, 2014	Nov. 30, 2013	Aug. 31, 2013	Jun. 01, 2013	Mar. 02, 2013	Nov. 24, 2012	Aug. 25, 2012	May 26, 2012	Mar. 01, 2014	Mar. 02, 2013	Feb. 25, 2012
Numerator:
Net income (loss)	$ 18,340	$ (9,486)	$ 4,107	$ (4,795)	$ 2,092	$ 6,862	$ 3,360	$ (12,445)	$ 8,166	$ (130)	$ (30,671)
Less: Distributions accumulated to preferred shareholders									(59,747)	(90,349)	(78,575)
Net loss available to common shareholders	$ 18,340	$ (25,083)	$ (17,744)	$ (27,094)	$ (22,847)	$ (15,594)	$ (18,438)	$ (33,601)	$ (51,581)	$ (90,479)	$ (109,246)
Denominator:
Weighted average common shares outstanding - basic and diluted					2,929,411	2,928,964	2,929,570	2,931,250	17,955,757	2,929,789	2,931,996
Basic and diluted net loss per common share (in dollars per share)	$ 0.38	$ (1.39)	$ (6.06)	$ (9.25)	$ (7.80)	$ (5.32)	$ (6.29)	$ (11.46)	$ (2.87)	$ (30.88)	$ (37.26)
Antidilutive securities not included:
Stock options outstanding									373,414