Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Statement of Cash Flows [Abstract]
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, BEGINNING OF PERIOD	$ 32,173	$ 21,856	$ 17,616	$ 16,301
OPERATING ACTIVITIES:
Net income	3,561	1,629	12,005	3,938
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization of property and equipment and capitalized content costs, operating lease assets, and other	4,854	3,671	16,524	12,714
Stock-based compensation	1,274	1,182	5,509	4,605
Other operating expense (income), net	(13)	56	205	216
Other expense (income), net	(135)	(184)	268	(437)
Deferred income taxes	415	141	714	134
Changes in operating assets and liabilities:
Inventories	719	2,220	(2,815)	(2,309)
Accounts receivable, net and other	(401)	1,029	(6,043)	(4,716)
Accounts payable	(6,384)	(10,216)	7,095	3,749
Accrued expenses and other	(2,932)	(2,225)	(235)	(538)
Unearned revenue	888	906	1,133	838
Net cash provided by (used in) operating activities	1,846	(1,791)	34,360	18,194
INVESTING ACTIVITIES:
Purchases of property and equipment	(3,290)	(3,098)	(13,619)	(12,905)
Proceeds from property and equipment incentives	569	371	2,303	1,981
Acquisitions, net of cash acquired, and other	(1,169)	(13)	(3,342)	(13,939)
Sales and maturities of marketable securities	2,643	2,677	8,205	10,444
Purchases of marketable securities	(6,876)	(470)	(13,506)	(11,846)
Net cash provided by (used in) investing activities	(8,123)	(533)	(19,959)	(26,265)
FINANCING ACTIVITIES:
Proceeds from long-term debt and other	190	125	833	16,332
Repayments of long-term debt and other	(351)	(202)	(817)	(1,463)
Principal repayments of finance leases	(2,214)	(2,015)	(7,649)	(5,981)
Principal repayments of financing obligations	(2)	(72)	(266)	(235)
Net cash provided by (used in) financing activities	(2,377)	(2,164)	(7,899)	8,653
Foreign currency effect on cash, cash equivalents, and restricted cash	(12)	248	(611)	733
Net increase (decrease) in cash, cash equivalents, and restricted cash	(8,666)	(4,240)	5,891	1,315
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, END OF PERIOD	23,507	17,616	23,507	17,616
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest on long-term debt	286	282	858	607
Cash paid for operating leases	709	0	709	0
Cash paid for interest on finance leases	165	75	471	234
Cash paid for interest on financing obligations	2	54	142	153
Cash paid for income taxes, net of refunds	168	513	840	1,224
Assets acquired under operating leases	875	0	875	0
Property and equipment acquired under finance leases	2,628	2,270	10,972	10,020
Property and equipment acquired under build-to-suit arrangements	$ 436	$ 741	$ 3,336	$ 3,081