Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended	9 Months Ended
	Jan. 27, 2018	Jan. 27, 2018	Apr. 29, 2017	Jan. 28, 2017
Goodwill	$ 49,282,000	$ 49,282,000	$ 329,467,000	$ 281,346,000
Property, Plant and Equipment, Net	110,987,000	110,987,000	116,613,000	107,272,000
Intangible Assets, Net (Excluding Goodwill)	224,314,000	224,314,000	209,885,000	191,628,000
Goodwill, Impairment Loss	313,130	313,130,000
Liabilities, Current	741,156,000	741,156,000	$ 413,220,000	$ 688,109,000
Deferred Tax Asset Current [Member]
Liabilities, Noncurrent	54,370	54,370
Liabilities, Current	13,754	13,754
BNC [Member]
Goodwill	$ 0	$ 0