Segment Reporting Segment Reporting (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 28, 2018 USD ($) Person Store	Jan. 27, 2018 USD ($)	Oct. 28, 2017 USD ($)	Jul. 29, 2017 USD ($)	Apr. 29, 2017 USD ($)	Jan. 28, 2017 USD ($)	Oct. 29, 2016 USD ($)	Jul. 30, 2016 USD ($)	Apr. 28, 2018 USD ($) Person Store segment	Apr. 29, 2017 USD ($)	Apr. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Other Nonrecurring Expense									$ 313,130
Number of Reportable Segments									3	2
Number of Stores | Store	1,444								1,444
Revenue, Net	$ 357,654	$ 603,391	$ 886,861	$ 355,711	$ 342,830	$ 521,624	$ 770,671	$ 239,237	$ 2,203,617	$ 1,874,362	$ 1,808,029
Gross Profit	128,334	$ 146,999	$ 216,700	$ 65,200	123,025	$ 116,249	$ 171,954	$ 47,833	557,233	459,061	454,699
Depreciation and amortization expense									65,586	53,318	52,690
Operating Income (Loss)									(262,703)	13,555	4,623
Interest Income (Expense), Net									(10,306)	(3,464)	(1,872)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									(273,009)	10,091	2,751
Assets	1,039,211				1,299,832				1,039,211	1,299,832
Payments to Acquire Property, Plant, and Equipment									(42,809)	(34,670)	(50,790)
Goodwill	$ 49,282				329,467				$ 49,282	329,467	280,911
Number of Subscribers | Person	100,000								100,000
DSS [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Gross									$ 15,762	0	0
Gross Profit									15,403	0	0
Depreciation and amortization expense									5,253	0	0
Operating Income (Loss)									226	0	0
Assets	$ 36,743				0				36,743	0
Payments to Acquire Property, Plant, and Equipment									2,620	0	0
Goodwill	0				0				0	0
BNC [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Gross									1,816,083	1,845,561	1,808,029
Gross Profit									441,209	454,950	454,699
Depreciation and amortization expense									53,737	52,067	52,564
Operating Income (Loss)									(279,375)	53,674	45,042
Assets	443,541				838,680				443,541	838,680
Payments to Acquire Property, Plant, and Equipment									37,476	34,435	50,324
Goodwill	0				281,349				0	281,349
MBS [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Gross									459,529	34,091	0
Gross Profit									101,345	4,748	0
Depreciation and amortization expense									6,406	1,059	0
Operating Income (Loss)									44,920	(11,595)	0
Assets	287,507				251,028				287,507	251,028
Payments to Acquire Property, Plant, and Equipment									2,681	218	0
Goodwill	48,292				48,118				48,292	48,118
Eliminations [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Gross									(87,757)	(5,290)	0
Gross Profit									(724)	(637)	0
Operating Income (Loss)									(724)	(637)	0
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit										192	126
Depreciation and amortization expense									190
Operating Income (Loss)									(27,750)	(27,887)	(40,419)
Assets	$ 271,420				210,124				271,420	210,124
Payments to Acquire Property, Plant, and Equipment									32	17	$ 466
BNC [Member]
Segment Reporting Information [Line Items]
Other Nonrecurring Expense									$ 313,100
Number of Stores | Store	768								768
Goodwill	$ 0				281,349				$ 0	281,349
MBS [Member]
Segment Reporting Information [Line Items]
Number of Stores | Store	676								676
Number of System Customers | Store	430								430
Number of Wholesale Customers | Store									3,500
Goodwill	$ 49,282				$ 48,118				$ 49,282	$ 48,118