Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	$ 19,334	$ 15,890	$ 12,470	$ 10,237
OPERATING ACTIVITIES:
Net income	724	513	2,583	1,166
Adjustments to reconcile net income to net cash from operating activities:
Depreciation of property and equipment, including internal-use software and website development, and other amortization, including capitalized content costs	2,435	1,827	8,725	6,682
Stock-based compensation	792	544	3,223	2,257
Other operating expense, net	42	43	157	155
Other expense (income), net	(40)	(50)	(10)	108
Deferred income taxes	(22)	11	(279)	94
Changes in operating assets and liabilities:
Inventories	947	769	(1,249)	(2,138)
Accounts receivable, net and other	994	412	(2,785)	(1,784)
Accounts payable	(6,865)	(5,770)	3,935	2,773
Accrued expenses and other	(1,404)	(956)	1,277	893
Additions to unearned revenue	4,054	2,814	13,171	8,412
Amortization of previously unearned revenue	(3,247)	(2,110)	(11,114)	(7,055)
Net cash provided by (used in) operating activities	(1,590)	(1,953)	17,634	11,563
INVESTING ACTIVITIES:
Purchases of property and equipment, including internal-use software and website development, net	(1,861)	(1,179)	(7,417)	(4,897)
Acquisitions, net of cash acquired, and other	(45)	(16)	(146)	(446)
Sales and maturities of marketable securities	1,910	1,138	5,505	3,788
Purchases of marketable securities	(1,620)	(636)	(8,740)	(3,741)
Net cash provided by (used in) investing activities	(1,616)	(693)	(10,798)	(5,296)
FINANCING ACTIVITIES:
Proceeds from long-term debt and other	24	9	636	179
Repayments of long-term debt and other	(69)	(175)	(247)	(1,512)
Principal repayments of capital lease obligations	(832)	(801)	(3,891)	(2,761)
Principal repayments of finance lease obligations	(37)	(29)	(155)	(111)
Net cash provided by (used in) financing activities	(914)	(996)	(3,657)	(4,205)
Foreign currency effect on cash and cash equivalents	226	222	(209)	171
Net increase (decrease) in cash and cash equivalents	(3,894)	(3,420)	2,970	2,233
CASH AND CASH EQUIVALENTS, END OF PERIOD	15,440	12,470	15,440	12,470
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest on long-term debt	4	2	292	310
Cash paid for interest on capital and finance lease obligations	61	47	220	168
Cash paid for income taxes, net of refunds	246	139	520	357
Assets Held under Capital Leases
SUPPLEMENTAL CASH FLOW INFORMATION:
Property and equipment acquired	1,888	875	6,717	4,638
Assets Held under Build-To-Suit Leases
SUPPLEMENTAL CASH FLOW INFORMATION:
Property and equipment acquired	$ 1,200	$ 351	$ 2,057	$ 793