CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total Finisar Stockholders' Equity	Non-controlling Interest
Beginning balance at Apr. 30, 2012	$ 779,845	$ 91	$ 2,309,219	$ 28,720	$ (1,566,506)	$ 771,524	$ 8,321
Beginning balance (in shares) at Apr. 30, 2012		91,451,615
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(8,065)				(5,454)	(5,454)	(2,611)
Other comprehensive loss, net	(195)			(195)		(195)
Issuance of shares pursuant to equity plans, net of tax withholdings (in shares)		1,591,907
Issuance of shares pursuant to equity plans, net of tax withholdings	391	2	389			391
Issuance of shares pursuant to employee stock purchase plan (in shares)		577,136
Issuance of shares pursuant to employee stock purchase plan	6,641	1	6,640			6,641
Issuance of shares for exercise of warrants (in shares)		37,582
Issuance of shares for exercise of warrants	30		30			30
Share-based compensation expense	31,961		31,961			31,961
Employer contribution in defined contribution retirement plan (in shares)		120,380
Employer contribution to defined contribution retirement plan	1,907		1,907			1,907
Issuance of shares upon conversion of convertible debt	0
Ending balance at Apr. 28, 2013	812,515	94	2,350,146	28,525	(1,571,960)	806,805	5,710
Ending balance (in shares) at Apr. 28, 2013		93,778,620
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	111,537				111,787	111,787	(250)
Other comprehensive loss, net	(8,500)			(8,500)		(8,500)
Issuance of shares pursuant to equity plans, net of tax withholdings (in shares)		2,805,276
Issuance of shares pursuant to equity plans, net of tax withholdings	9,293	3	9,290			9,293
Issuance of shares pursuant to employee stock purchase plan (in shares)		608,946
Issuance of shares pursuant to employee stock purchase plan	7,563	0	7,563			7,563
Share-based compensation expense	37,966		37,966			37,966
Employer contribution in defined contribution retirement plan (in shares)		88,823
Employer contribution to defined contribution retirement plan	2,228		2,228			2,228
Equity component of senior convertible notes, net of allocated issuance costs	48,917		48,917			48,917
Sale of controlling interest	(5,460)						(5,460)
Issuance of shares upon conversion of convertible debt	0
Ending balance at Apr. 27, 2014	1,016,059	97	2,456,110	20,025	(1,460,173)	1,016,059	0
Ending balance (in shares) at Apr. 27, 2014		97,281,665
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	11,887				11,887	11,887	0
Other comprehensive loss, net	(19,164)			(19,164)		(19,164)
Issuance of shares pursuant to equity plans, net of tax withholdings (in shares)		2,453,668
Issuance of shares pursuant to equity plans, net of tax withholdings	(751)	3	(754)			(751)
Issuance of shares pursuant to employee stock purchase plan (in shares)		525,032
Issuance of shares pursuant to employee stock purchase plan	8,584	0	8,584			8,584
Share-based compensation expense	44,600		44,600			44,600
Employer contribution in defined contribution retirement plan (in shares)	122,979	122,979
Employer contribution to defined contribution retirement plan	2,563		2,563			2,563
Issuance of shares upon conversion of convertible debt (in shares)		3,748,473
Issuance of shares upon conversion of convertible debt	40,015	4	40,011			40,015
Ending balance at May. 03, 2015	$ 1,103,793	$ 104	$ 2,551,114	$ 861	$ (1,448,286)	$ 1,103,793	$ 0
Ending balance (in shares) at May. 03, 2015		104,131,817