SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended								12 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2009
Statement of Operations Data:
Revenues	$ 213,680	$ 190,941	$ 182,726	$ 170,808	$ 195,248	$ 190,640	$ 204,973	$ 187,330	$ 758,155	$ 778,191	$ 843,760
Cost of revenues	80,574	68,181	65,722	59,179	69,186	66,455	74,701	69,463
Selling, general and administrative	60,672	57,562	55,185	51,614	51,733	52,545	53,721	45,196	225,033	203,195	212,735
Research and development costs	23,254	22,088	21,360	21,384	20,980	20,279	19,571	19,471	88,086	80,301	77,277
Impairment charges						11,379				11,379
Income from continuing operations before income taxes	38,411	37,429	33,616	33,937	44,334	31,992	48,629	45,863	143,393	170,818	184,960
Income tax expense	(12,899)	(13,651)	(6,347)	(12,285)	(16,748)	(11,262)	(16,456)	(16,255)	(45,182)	(60,721)	(64,781)
Income from continuing operations	25,512	23,778	27,269	21,652	27,586	20,730	32,173	29,608	98,211	110,097	120,179
Income from discontinued operations, net of tax					1,639	2,363	1,430	1,749		7,181	8,057
Gain (loss) on sale of discontinued operations, net of tax				(403)	22,079				(403)	22,079
Net income	25,512	23,778	27,269	21,249	51,304	23,093	33,603	31,357	97,808	139,357	128,236
Less net income (loss) attributable to noncontrolling interests	56	12	17	(540)	263	534	350	733	(455)	1,880	1,927
Net income attributable to Bally Technologies, Inc.	$ 25,456	$ 23,766	$ 27,252	$ 21,789	$ 51,041	$ 22,559	$ 33,253	$ 30,624	$ 98,263	$ 137,477	$ 126,309
Basic earnings per share attributable to Bally Technologies, Inc.:
Income from continuing operations (in dollars per share)	$ 0.53	$ 0.45	$ 0.51	$ 0.42	$ 0.50	$ 0.37	$ 0.59	$ 0.53	$ 1.90	$ 2.00	$ 2.19
Income from discontinued operations (in dollars per share)					$ 0.03	$ 0.04	$ 0.02	$ 0.03		$ 0.11	$ 0.13
Gain (loss) on sale of discontinued operations (in dollars per share)				$ (0.01)	$ 0.40				$ (0.01)	$ 0.41
Basic earnings per share (in dollars per share)	$ 0.53	$ 0.45	$ 0.51	$ 0.41	$ 0.93	$ 0.41	$ 0.61	$ 0.56	$ 1.89	$ 2.52	$ 2.32
Diluted earnings per share attributable to Bally Technologies, Inc.:
Income from continuing operations (in dollars per share)	$ 0.51	$ 0.43	$ 0.49	$ 0.40	$ 0.48	$ 0.36	$ 0.56	$ 0.50	$ 1.82	$ 1.89	$ 2.10
Income from discontinued operations (in dollars per share)					$ 0.03	$ 0.03	$ 0.02	$ 0.03		$ 0.11	$ 0.12
Gain (loss) on sale of discontinued operations (in dollars per share)				$ (0.01)	$ 0.38				$ (0.01)	$ 0.38
Diluted earnings per share (in dollars per share)	$ 0.51	$ 0.43	$ 0.49	$ 0.39	$ 0.89	$ 0.39	$ 0.58	$ 0.53	$ 1.81	$ 2.38	$ 2.22