SUPPLEMENTAL GUARANTOR INFORMATION (Condensed Balance Sheets) (Details) - USD ($) $ in Millions		Mar. 31, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
Current assets
Cash and cash equivalents		$ 605	$ 1,188	$ 1,136	$ 1,257
Accounts receivable	[1]	972	894
Inventories		687	671
Other assets		113	113
Total current assets		2,377	2,866
Noncurrent assets
Property, plant and equipment, net		2,205	2,224
Goodwill		2,413	2,401
Intangibles		1,017	1,064
Restricted investments		298	292
Asbestos insurance receivable		193	196
Equity and other unconsolidated investments		61	57
Investment in subsidiaries		0	0
Deferred income taxes		199	177
Intercompany receivables		0	0
Other assets		423	420
Total noncurrent assets		6,809	6,831
Total assets		9,186	9,697
Current liabilities
Short-term debt		95	170
Current portion of long-term debt		16	19
Accounts payable and other accrued liabilities		926	1,027
Total current liabilities		1,037	1,216
Noncurrent liabilities
Long-term debt		2,812	3,055
Employee benefit obligations		1,017	1,080
Asbestos litigation reserve		663	686
Deferred income taxes		69	69
Intercompany payables		0	0
Other liabilities		445	426
Total noncurrent liabilities		5,006	5,316
Equity
Total Ashland stockholders’ equity		3,300	3,347
Noncontrolling interest		(157)	(182)
Total equity		3,143	3,165
Total liabilities and equity		9,186	9,697
Eliminations
Current assets
Cash and cash equivalents		0	0	0	0
Accounts receivable		0	0
Inventories		0	0
Other assets		(3)	(8)
Total current assets		(3)	(8)
Noncurrent assets
Property, plant and equipment, net		0	0
Goodwill		0	0
Intangibles		0	0
Restricted investments		0	0
Asbestos insurance receivable		0	0
Equity and other unconsolidated investments		0	0
Investment in subsidiaries		(10,830)	(10,724)
Deferred income taxes		(127)	(97)
Intercompany receivables		(2,530)	(2,269)
Other assets		0	0
Total noncurrent assets		(13,487)	(13,090)
Total assets		(13,490)	(13,098)
Current liabilities
Short-term debt		0	0
Current portion of long-term debt		0	0
Accounts payable and other accrued liabilities		(3)	(8)
Total current liabilities		(3)	(8)
Noncurrent liabilities
Long-term debt		0	0
Employee benefit obligations		0	0
Asbestos litigation reserve		0	0
Deferred income taxes		(127)	(97)
Intercompany payables		(2,530)	(2,269)
Other liabilities		0	0
Total noncurrent liabilities		(2,657)	(2,366)
Equity
Total Ashland stockholders’ equity		(10,830)	(10,724)
Noncontrolling interest		0	0
Total equity		(10,830)	(10,724)
Total liabilities and equity		(13,490)	(13,098)
Ashland Global Holdings Inc. (Parent Guarantor)
Current assets
Cash and cash equivalents		0	0	0	0
Accounts receivable		0	0
Inventories		0	0
Other assets		0	7
Total current assets		0	7
Noncurrent assets
Property, plant and equipment, net		0	0
Goodwill		0	0
Intangibles		0	0
Restricted investments		0	0
Asbestos insurance receivable		0	0
Equity and other unconsolidated investments		0	0
Investment in subsidiaries		3,195	3,127
Deferred income taxes		31	31
Intercompany receivables		0	0
Other assets		0	0
Total noncurrent assets		3,226	3,158
Total assets		3,226	3,165
Current liabilities
Short-term debt		0	0
Current portion of long-term debt		0	0
Accounts payable and other accrued liabilities		64	0
Total current liabilities		64	0
Noncurrent liabilities
Long-term debt		0	0
Employee benefit obligations		0	0
Asbestos litigation reserve		0	0
Deferred income taxes		0	0
Intercompany payables		19	0
Other liabilities		0	0
Total noncurrent liabilities		19	0
Equity
Total Ashland stockholders’ equity		3,143	3,165
Noncontrolling interest		0	0
Total equity		3,143	3,165
Total liabilities and equity		3,226	3,165
Ashland LLC (Issuer)
Current assets
Cash and cash equivalents		108	76	11	21
Accounts receivable		17	18
Inventories		47	42
Other assets		6	16
Total current assets		178	152
Noncurrent assets
Property, plant and equipment, net		240	246
Goodwill		141	141
Intangibles		34	35
Restricted investments		0	0
Asbestos insurance receivable		130	133
Equity and other unconsolidated investments		2	2
Investment in subsidiaries		7,635	7,597
Deferred income taxes		96	97
Intercompany receivables		13	5
Other assets		256	253
Total noncurrent assets		8,547	8,509
Total assets		8,725	8,661
Current liabilities
Short-term debt		0	0
Current portion of long-term debt		0	0
Accounts payable and other accrued liabilities		214	244
Total current liabilities		214	244
Noncurrent liabilities
Long-term debt		2,103	2,182
Employee benefit obligations		38	44
Asbestos litigation reserve		363	381
Deferred income taxes		0	0
Intercompany payables		2,498	2,264
Other liabilities		224	220
Total noncurrent liabilities		5,226	5,091
Equity
Total Ashland stockholders’ equity		3,285	3,326
Noncontrolling interest		0	0
Total equity		3,285	3,326
Total liabilities and equity		8,725	8,661
Other Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents		497	1,112	$ 1,125	$ 1,236
Accounts receivable		955	876
Inventories		640	629
Other assets		110	98
Total current assets		2,202	2,715
Noncurrent assets
Property, plant and equipment, net		1,965	1,978
Goodwill		2,272	2,260
Intangibles		983	1,029
Restricted investments		298	292
Asbestos insurance receivable		63	63
Equity and other unconsolidated investments		59	55
Investment in subsidiaries		0	0
Deferred income taxes		199	146
Intercompany receivables		2,517	2,264
Other assets		167	167
Total noncurrent assets		8,523	8,254
Total assets		10,725	10,969
Current liabilities
Short-term debt		95	170
Current portion of long-term debt		16	19
Accounts payable and other accrued liabilities		651	791
Total current liabilities		762	980
Noncurrent liabilities
Long-term debt		709	873
Employee benefit obligations		979	1,036
Asbestos litigation reserve		300	305
Deferred income taxes		196	166
Intercompany payables		13	5
Other liabilities		221	206
Total noncurrent liabilities		2,418	2,591
Equity
Total Ashland stockholders’ equity		7,702	7,580
Noncontrolling interest		(157)	(182)
Total equity		7,545	7,398
Total liabilities and equity		$ 10,725	$ 10,969

[1] Accounts receivable includes an allowance for doubtful accounts of $14 million at March 31, 2017 and September 30, 2016