Indemnity Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Amounts reclassified out of accumulated other comprehensive income (loss) and the related affected line item in the Consolidated Statements of Operations where net income is presented
Net realized investment gains (losses)	$ 61	$ (107)	$ 310	$ 189
Net impairment losses recognized in earnings	(1.0)	0	(1.0)	0
Income (loss) from operations before income taxes and noncontrolling interest	263	(70)	699	464
Provision for income taxes	86	(32)	232	148
Net income (loss)	177	(38)	467	316	619
Less: Net income attributable to noncontrolling interest in consolidated entity – Exchange	133	(81)	386	237
Net income attributable to Indemnity	44	43	81	79
Amounts reclassified from accumulated other comprehensive income (loss)(1)
Amounts reclassified out of accumulated other comprehensive income (loss) and the related affected line item in the Consolidated Statements of Operations where net income is presented
Net income attributable to Indemnity	0		0
Unrealized holding gains (losses) on available-for-sale securities | Amounts reclassified from accumulated other comprehensive income (loss)(1)
Amounts reclassified out of accumulated other comprehensive income (loss) and the related affected line item in the Consolidated Statements of Operations where net income is presented
Net realized investment gains (losses)	6		21
Net impairment losses recognized in earnings	(1.0)		(1.0)
Income (loss) from operations before income taxes and noncontrolling interest	5		20
Provision for income taxes	2		7
Net income (loss)	3		13
Less: Net income attributable to noncontrolling interest in consolidated entity – Exchange	3		13
Net income attributable to Indemnity	0		0
Amortization of postretirement plan items | Amounts reclassified from accumulated other comprehensive income (loss)(1)
Amounts reclassified out of accumulated other comprehensive income (loss) and the related affected line item in the Consolidated Statements of Operations where net income is presented
Net income attributable to Indemnity	$ 0		$ 0