Finance Receivables - Allowance for Loan Losses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for loan losses	$ 155	$ 135
Consumer Finance Receivables [Member] | Post-Acquisition Portfolio
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	655	497
Provision for loan losses	157	137
Charge-offs	(234)	(224)
Recoveries	122	127
Foreign currency translation	(8)	0
Balance at end of period	692	537
Consumer Finance Receivables [Member] | North America Segment [Member] | Post-Acquisition Portfolio
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	577	468
Provision for loan losses	118	104
Charge-offs	(200)	(192)
Recoveries	110	111
Foreign currency translation	0	0
Balance at end of period	605	491
Consumer Finance Receivables [Member] | International Segment [Member] | Post-Acquisition Portfolio
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	78	29
Provision for loan losses	39	33
Charge-offs	(34)	(32)
Recoveries	12	16
Foreign currency translation	(8)	0
Balance at end of period	$ 87	$ 46