Segment Information (Details 1) (USD $)	3 Months Ended		12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Jan. 31, 2012
Reconciliation of EBDT to Net Earnings (Loss) by Segment
EBDT	$ 102,432,000	$ 127,376,000
Depreciation and amortization - Real Estate Groups	(52,833,000)	(55,853,000)
Amortization of mortgage procurement costs	(2,869,000)	(2,882,000)
Straight-line rent adjustment	4,832,000	1,888,000
Impairment of real estate	(1,381,000)	(4,835,000)
Preference payment		(585,000)
Gain on disposition of partial interests in rental properties	0	9,561,000
Gain on disposition of unconsolidated entities		12,567,000
Allowance for projects under development revision (See Note A)		(2,000,000)
Discontinued operations:
Straight-line rent adjustment	3,000	336,000
Gain on disposition of rental properties	7,914,000	10,038,000
Income tax benefit (expense) on non-operating earning (loss) - current and deferred:
Deferred income taxes	(11,463,000)	(4,037,000)
Current income taxes attributable to above dispositions	(5,545,000)	(31,505,000)
Net earnings attributable to Forest City Enterprises, Inc.	22,752,000	46,343,000
Preferred dividends	(3,850,000)	(3,850,000)	(15,400,000)
Net earnings (loss) attributable to Forest City Enterprises, Inc. common shareholders	18,902,000	42,493,000
Real Estate Groups [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
Depreciation and amortization - Real Estate Groups	(70,417,000)	(67,203,000)
Amortization of mortgage procurement costs	(3,623,000)	(3,370,000)
Discontinued operations:
Amortization of mortgage procurement costs - Real Estate Groups		(262,000)
Depreciation and amortization - Real Estate Groups		(1,626,000)
Commercial Group [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
EBDT	98,226,000	115,279,000
Depreciation and amortization - Real Estate Groups	(39,534,000)	(41,995,000)
Straight-line rent adjustment	4,914,000	2,051,000
Impairment of real estate	(1,381,000)	(3,435,000)
Preference payment		(585,000)
Gain on disposition of partial interests in rental properties		9,561,000
Allowance for projects under development revision (See Note A)		(1,400,000)
Discontinued operations:
Straight-line rent adjustment	3,000	336,000
Gain on disposition of rental properties	7,914,000	10,038,000
Income tax benefit (expense) on non-operating earning (loss) - current and deferred:
Net earnings attributable to Forest City Enterprises, Inc.	57,659,000	78,684,000
Net earnings (loss) attributable to Forest City Enterprises, Inc. common shareholders	57,659,000	78,684,000
Commercial Group [Member] | Real Estate Groups [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
Depreciation and amortization - Real Estate Groups	(49,178,000)	(48,804,000)
Amortization of mortgage procurement costs	(2,839,000)	(2,469,000)
Discontinued operations:
Amortization of mortgage procurement costs - Real Estate Groups		(262,000)
Depreciation and amortization - Real Estate Groups		(1,626,000)
Residential Group [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
EBDT	32,779,000	26,851,000
Depreciation and amortization - Real Estate Groups	(12,863,000)	(13,445,000)
Straight-line rent adjustment	(82,000)	(163,000)
Gain on disposition of unconsolidated entities		12,567,000
Allowance for projects under development revision (See Note A)		(600,000)
Income tax benefit (expense) on non-operating earning (loss) - current and deferred:
Net earnings attributable to Forest City Enterprises, Inc.	10,808,000	19,502,000
Net earnings (loss) attributable to Forest City Enterprises, Inc. common shareholders	10,808,000	19,502,000
Residential Group [Member] | Real Estate Groups [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
Depreciation and amortization - Real Estate Groups	(21,131,000)	(18,313,000)
Amortization of mortgage procurement costs	(758,000)	(840,000)
Land Development Group [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
EBDT	1,090,000	1,106,000
Depreciation and amortization - Real Estate Groups	(107,000)	(60,000)
Impairment of real estate		(1,400,000)
Income tax benefit (expense) on non-operating earning (loss) - current and deferred:
Net earnings attributable to Forest City Enterprises, Inc.	956,000	(441,000)
Net earnings (loss) attributable to Forest City Enterprises, Inc. common shareholders	956,000	(441,000)
Land Development Group [Member] | Real Estate Groups [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
Depreciation and amortization - Real Estate Groups	(108,000)	(86,000)
Amortization of mortgage procurement costs	(26,000)	(61,000)
The Nets [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
EBDT	(6,958,000)	(304,000)
Depreciation and amortization - Real Estate Groups
Income tax benefit (expense) on non-operating earning (loss) - current and deferred:
Net earnings attributable to Forest City Enterprises, Inc.	(6,958,000)	(304,000)
Net earnings (loss) attributable to Forest City Enterprises, Inc. common shareholders	(6,958,000)	(304,000)
Corporate Activities [Member]
Reconciliation of EBDT to Net Earnings (Loss) by Segment
EBDT	(22,705,000)	(15,556,000)
Depreciation and amortization - Real Estate Groups	(329,000)	(353,000)
Income tax benefit (expense) on non-operating earning (loss) - current and deferred:
Deferred income taxes	(11,463,000)	(4,037,000)
Current income taxes attributable to above dispositions	(5,545,000)	(31,505,000)
Net earnings attributable to Forest City Enterprises, Inc.	(39,713,000)	(51,098,000)
Preferred dividends	(3,850,000)	(3,850,000)
Net earnings (loss) attributable to Forest City Enterprises, Inc. common shareholders	$ (43,563,000)	$ (54,948,000)