Reinsurance - Effective Exit of GMDB and GMIB Business (Details) (USD $)	3 Months Ended			0 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2013 Variable Annuity [Member] Guaranteed Minimum Death Benefit [Member]	Feb. 04, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Variable Annuity [Member]	Mar. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Variable Annuity [Member]	Dec. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Variable Annuity [Member]	Mar. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Other Benefits Expense [Member] Variable Annuity [Member]	Mar. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Guaranteed Minimum Income Benefits Fair Value Gain Loss [Member] Variable Annuity [Member]	Mar. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Other Operating Expenses [Member] Variable Annuity [Member]
Ceded Credit Risk [Line Items]
Ceded Reinsurance Agreement, Coverage Limit, Fixed Portion				$ 3,800,000,000
Ceded Reinsurance Agreement Charge, After-tax					507,000,000
Ceded Reinsurance Agreement Charge, Pre-tax					781,000,000		727,000,000	45,000,000	9,000,000
Reinsurance preimums paid	0	1,475,000,000		2,200,000,000		1,647,000,000
Derivative Gain (Loss)			$ (32,000,000)