Fair Value Measurement of Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Funds receivable and customer accounts	10,545	$ 9,260
Derivative Assets	222	44
Foreign Exchange Contract
Fair Value Disclosure, additional details
Derivative lower range (in months)	1 month
Derivative higher range (in years)	1 year
Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,770	4,531
Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	5,552	4,696
Fair Value Disclosure, additional details
Cost and equity method investments included in long-term investments	225	269
Corporate Debt Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	2,519	3,529
Corporate Debt Securities [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	5,319	4,445
Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	1,038	893
Equity Securities [Member] | Long-Term Investment [Member]
Fair Value Disclosure, additional details
Cost and equity method investments included in long-term investments	225	269
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Cash and cash equivalents	6,328	4,494
Funds receivable and customer accounts	4,161
Total financial assets	20,033	17,328
Fair Value, Measurements, Recurring [Member] | Other Current Assets [Member] | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Assets	222	44
Fair Value, Measurements, Recurring [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,770	4,531
Fair Value, Measurements, Recurring [Member] | Funds Receivable And Customer Accounts [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Funds receivable and customer accounts		3,563
Fair Value, Measurements, Recurring [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	5,552	4,696
Fair Value, Measurements, Recurring [Member] | Other Current Liabilities [Member] | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivatives liabilities	29	151
Fair Value, Measurements, Recurring [Member] | Restricted Cash [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	29	17
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	2,519	3,529
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	5,319	4,445
Fair Value, Measurements, Recurring [Member] | US Treasury And Government, And Foreign Government Debt Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3	43
Fair Value, Measurements, Recurring [Member] | US Treasury And Government, And Foreign Government Debt Securities [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	233	251
Fair Value, Measurements, Recurring [Member] | Bank Time Deposits [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	181	49
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	1,038	893
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Cash and cash equivalents	3,917	4,159
Funds receivable and customer accounts	0
Total financial assets	4,984	5,069
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Current Assets [Member] | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Assets	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	1,067	910
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Funds Receivable And Customer Accounts [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Funds receivable and customer accounts		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Current Liabilities [Member] | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivatives liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Restricted Cash [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	29	17
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury And Government, And Foreign Government Debt Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury And Government, And Foreign Government Debt Securities [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Bank Time Deposits [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	1,038	893
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Cash and cash equivalents	2,411	335
Funds receivable and customer accounts	4,161
Total financial assets	15,049	12,259
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Current Assets [Member] | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Assets		44
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	2,703	3,621
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Funds Receivable And Customer Accounts [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Funds receivable and customer accounts		3,563
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	5,552	4,696
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Current Liabilities [Member] | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivatives liabilities	29	151
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Restricted Cash [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	2,519	3,529
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	5,319	4,445
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury And Government, And Foreign Government Debt Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3	43
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury And Government, And Foreign Government Debt Securities [Member] | Long-Term Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	233	251
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Bank Time Deposits [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	181	49
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Bank Time Deposits [Member]
Fair Value Disclosure, additional details
Held-to-maturity securities		6
Cash Flow Hedging | Designated as Hedging Instrument | Foreign Exchange Contract
Fair Value Disclosure, additional details
Derivative higher range (in years)	18 months
Cash Flow Hedging | Designated as Hedging Instrument | Other Current Assets [Member] | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Assets	170	$ 15