Correction of Consolidated Financial Statements (Quarterly Financial Data) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Apr. 25, 2014	Jan. 24, 2014	Oct. 25, 2013	Jul. 26, 2013	Apr. 26, 2013	Jan. 25, 2013	Oct. 26, 2012	Jul. 27, 2012	Apr. 25, 2014	Apr. 26, 2013	Apr. 27, 2012
Net Sales	$ 326,371	$ 340,132	$ 332,600	$ 329,449	$ 333,909	$ 343,321	$ 329,555	$ 323,441	$ 1,328,552	$ 1,330,226	$ 1,287,210
Operating income from continuing operations	4,277	7,954	8,895	11,999	22,239	19,119	21,976	24,620	33,125	87,954	106,475
Net income	13,009	6,181	6,119	8,376	29,781	(55,779)	10,383	14,794	33,685	(821)	72,942
Earnings Per Share - Income from Continuing Operations
Basic	$ 0.40	$ 0.25	$ 0.23	$ 0.30	$ 1.07	$ 0.87	$ 0.48	$ 0.53	$ 1.17	$ 2.94	$ 2.38
Diluted	$ 0.40	$ 0.24	$ 0.23	$ 0.30	$ 1.05	$ 0.86	$ 0.47	$ 0.52	$ 1.16	$ 2.90	$ 2.35
Earnings Per Share — Income (Loss) from Discontinued Operations
Basic	$ 0.13	$ (0.01)	$ 0.00	$ 0.00	$ 0.01	$ (2.87)	$ (0.11)	$ 0.00	$ 0.10	$ (2.97)	$ 0.09
Diluted	$ 0.13	$ (0.01)	$ 0.00	$ 0.00	$ 0.01	$ (2.82)	$ (0.11)	$ 0.00	$ 0.10	$ (2.93)	$ 0.09
Earnings per share - Net Income (Loss)
Basic	$ 0.53	$ 0.23	$ 0.22	$ 0.30	$ 1.07	$ (2.00)	$ 0.37	$ 0.53	$ 1.27	$ (0.03)	$ 2.48
Diluted	$ 0.53	$ 0.23	$ 0.22	$ 0.30	$ 1.06	$ (1.96)	$ 0.36	$ 0.52	$ 1.26	$ (0.03)	$ 2.44
As Reported
Net Sales		340,132		329,449	353,877	434,440	410,877	409,715		1,608,909	1,654,413
Operating income from continuing operations		7,954		11,999	(38,490)	(47,388)	16,757	25,264		(43,857)	107,874
Net income		5,723		9,153	27,024	(55,236)	10,342	15,008		(2,862)	72,850
Earnings Per Share - Income from Continuing Operations
Basic		$ 0.23		$ 0.33
Diluted		$ 0.23		$ 0.33
Earnings Per Share — Income (Loss) from Discontinued Operations
Basic		$ (0.01)		$ 0.00
Diluted		$ (0.01)		$ 0.00
Earnings per share - Net Income (Loss)
Basic		$ 0.22		$ 0.33	$ 0.97	$ (1.97)	$ 0.36	$ 0.53		$ (0.10)	$ 2.45
Diluted		$ 0.22		$ 0.33	$ 0.97	$ (1.97)	$ 0.36	$ 0.53		$ (0.10)	$ 2.45
As Recast
Net Sales		340,132		329,449	333,909	343,321	329,555	323,441		1,330,226	1,288,398
Operating income from continuing operations		7,954		11,999	22,967	20,202	23,526	25,511		92,206	106,806
Net income		5,723		9,153	27,024	(55,236)	10,342	15,008		(2,862)	72,850
Earnings Per Share - Income from Continuing Operations
Basic		$ 0.23		$ 0.33	$ 1.03	$ 0.83	$ 0.51	$ 0.53		$ 2.90	$ 2.39
Diluted		$ 0.23		$ 0.33	$ 1.02	$ 0.82	$ 0.50	$ 0.53		$ 2.86	$ 2.36
Earnings Per Share — Income (Loss) from Discontinued Operations
Basic		$ (0.01)		$ 0.00	$ (0.06)	$ (2.81)	$ (0.15)	$ 0.00		$ (3.00)	$ 0.08
Diluted		$ (0.01)		$ 0.00	$ (0.06)	$ (2.76)	$ (0.14)	$ 0.00		$ (2.96)	$ 0.08
Earnings per share - Net Income (Loss)
Basic		$ 0.22		$ 0.33	$ 0.97	$ (1.98)	$ 0.37	$ 0.53		$ (0.10)	$ 2.47
Diluted		$ 0.21		$ 0.33	$ 0.96	$ (1.94)	$ 0.36	$ 0.53		$ (0.10)	$ 2.43
Adjustments
Net Sales		0		0	0	0	0	0		0	(1,188)
Operating income from continuing operations		0		0	(728)	(1,083)	(1,550)	(891)		(4,252)	(331)
Net income		$ 458		$ (777)	$ 2,757	$ (543)	$ 41	$ (214)		$ 2,041	$ 92
Earnings Per Share - Income from Continuing Operations
Basic		$ 0.02		$ (0.03)	$ 0.03	$ 0.04	$ (0.03)	$ 0.00		$ 0.04	$ (0.01)
Diluted		$ 0.02		$ (0.03)	$ 0.03	$ 0.04	$ (0.03)	$ 0.00		$ 0.04	$ (0.01)
Earnings Per Share — Income (Loss) from Discontinued Operations
Basic		$ 0.00		$ 0.00	$ 0.07	$ (0.06)	$ 0.03	$ 0.00		$ 0.03	$ 0.02
Diluted		$ 0.00		$ 0.00	$ 0.07	$ (0.06)	$ 0.03	$ 0.00		$ 0.03	$ 0.02
Earnings per share - Net Income (Loss)
Basic		$ 0.02		$ (0.03)	$ 0.10	$ (0.02)	$ 0.00	$ (0.01)		$ 0.07	$ 0.00
Diluted		$ 0.02		$ (0.03)	$ 0.10	$ (0.02)	$ 0.00	$ (0.01)		$ 0.07	$ 0.00