Indemnity Accumulated Other Comprehensive Income (Loss) (Details) - Indemnity - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Changes in Indemnity's accumulated other comprehensive income (loss) by component attributable to the Indemnity shareholder interest
Balance, beginning of period	$ (118)	$ (59)
Other comprehensive income (loss) before reclassifications, net of tax	(3)	(63)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	4
Net current period other comprehensive income (loss), net of tax	(3)	(59)
Balance, end of period	(121)	(118)
Unrealized holding gains (losses) on available-for-sale securities
Changes in Indemnity's accumulated other comprehensive income (loss) by component attributable to the Indemnity shareholder interest
Balance, beginning of period	7	6
Other comprehensive income (loss) before reclassifications, net of tax	(3)	2
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	(1)
Net current period other comprehensive income (loss), net of tax	(3)	1
Balance, end of period	4	7
Postretirement plans
Changes in Indemnity's accumulated other comprehensive income (loss) by component attributable to the Indemnity shareholder interest
Balance, beginning of period	(125)	(65)
Other comprehensive income (loss) before reclassifications, net of tax	0	(65)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	5
Net current period other comprehensive income (loss), net of tax	0	(60)
Balance, end of period	$ (125)	$ (125)