CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Net revenues	$ 13,094	$ 10,842	$ 9,248
Operating expenses:
Transaction expense	4,419	3,346	2,610
Transaction and loan losses	1,011	1,088	809
Customer support and operations	1,364	1,267	1,110
Sales and marketing	1,128	969	937
Product development	953	834	792
General and administrative	1,155	1,028	873
Depreciation and amortization	805	724	608
Restructuring and other charges	132	0	48
Total operating expenses	10,967	9,256	7,787
Operating income	2,127	1,586	1,461
Other income (expense), net	73	45	27
Income before income taxes	2,200	1,631	1,488
Income tax expense	405	230	260
Net income	$ 1,795	$ 1,401	$ 1,228
Net income per share:
Basic (in usd per share)	$ 1.49	$ 1.16	$ 1.00
Diluted (in usd per share)	$ 1.47	$ 1.15	$ 1.00
Weighted average shares:
Basic (in shares)	1,203	1,210	1,222
Diluted (in shares)	1,221	1,218	1,229