Capitalized Software Development Costs (Details) (Indemnity, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Indemnity
Total capitalized software development costs subject to amortization and the related amortization expense
Gross carrying amount	$ 54	$ 43	$ 32
Accumulated amortization	(11)	(5)	(1)
Net carrying amount	43	38	31
Amortization expense	6	4	1
Estimated future amortization expenses related to capitalized software development costs
2013	7
2014	7
2015	8
2016	8
2017	$ 7