Summary of Significant Accounting Policies - Schedule of Impact of Adoption on Consolidated Statement of Balance Sheet (Detail) - USD ($) $ in Millions	Jun. 30, 2019	Mar. 31, 2019	Oct. 01, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017
Assets
Accounts receivable, net	$ 744			$ 447
Total current assets	1,580			1,176
Other assets	158			78
Deferred tax assets, net	7			11
Total assets	5,955			5,344
Liabilities and Equity
Accounts payable	208			281
Accrued royalties	1,577			1,396
Accrued liabilities	448			423
Deferred revenue	170			208
Other current liabilities	123			34
Total current liabilities	2,544			2,373
Deferred tax liabilities, net	236			165
Other noncurrent liabilities	302			307
Total liabilities	6,088			5,664
Equity:
Accumulated deficit	(1,061)			(1,272)
Noncontrolling interest	19			14
Total equity	(133)	$ (120)		(320)	$ 191	$ 205	$ 308
Total liabilities and equity	5,955			$ 5,344
Topic 606
Assets
Accounts receivable, net			$ 704
Total current assets			1,433
Other assets			93
Total assets			5,616
Liabilities and Equity
Accrued royalties			1,475
Accrued liabilities			422
Deferred revenue			181
Other current liabilities			67
Total current liabilities			2,457
Deferred tax liabilities, net			202
Other noncurrent liabilities			308
Total liabilities			5,786
Equity:
Accumulated deficit			(1,133)
Noncontrolling interest			25
Total equity			(170)
Total liabilities and equity			5,616
Balances Without Adoption Of ASC 606 | Topic 606
Assets
Accounts receivable, net	465
Total current assets	1,301
Other assets	143
Deferred tax assets, net	7
Total assets	5,661
Liabilities and Equity
Accounts payable	209
Accrued royalties	1,501
Accrued liabilities	449
Deferred revenue	199
Other current liabilities	95
Total current liabilities	2,471
Deferred tax liabilities, net	189
Other noncurrent liabilities	298
Total liabilities	5,964
Equity:
Accumulated deficit	(1,221)
Noncontrolling interest	9
Total equity	(303)
Total liabilities and equity	5,661
Impact of Adoption | Topic 606
Assets
Accounts receivable, net	279		257
Total current assets	279		257
Other assets	15		15
Deferred tax assets, net	0
Total assets	294		272
Liabilities and Equity
Accounts payable	(1)
Accrued royalties	76		79
Accrued liabilities	(1)		(1)
Deferred revenue	(29)		(27)
Other current liabilities	28		33
Total current liabilities	73		84
Deferred tax liabilities, net	47		37
Other noncurrent liabilities	4		1
Total liabilities	124		122
Equity:
Accumulated deficit	160		139
Noncontrolling interest	10		11
Total equity	170		150
Total liabilities and equity	$ 294		$ 272