Reinsurance - Effective Exit of GMDB nd GMIB Business (Details) (USD $)	12 Months Ended						12 Months Ended			12 Months Ended			3 Months Ended		12 Months Ended					3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Guaranteed Minimum Income Benefit [Member]	Dec. 31, 2012 Guaranteed Minimum Income Benefit [Member]	Dec. 31, 2013 Variable Annuity [Member]	Dec. 31, 2012 Variable Annuity [Member] Guaranteed Minimum Death Benefit [Member]	Dec. 31, 2011 Variable Annuity [Member] Guaranteed Minimum Death Benefit [Member]	Dec. 31, 2013 Variable Annuity [Member] Guaranteed Minimum Death Benefit [Member]	Dec. 31, 2013 Other Revenues [Member] Variable Annuity [Member] Guaranteed Minimum Death Benefit [Member]	Dec. 31, 2012 Other Revenues [Member] Variable Annuity [Member] Guaranteed Minimum Death Benefit [Member]	Dec. 31, 2011 Other Revenues [Member] Variable Annuity [Member] Guaranteed Minimum Death Benefit [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]	Dec. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Variable Annuity [Member] Guaranteed Minimum Death Benefit [Member]	Dec. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Variable Annuity [Member] Guaranteed Minimum Income Benefit [Member]	Dec. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Minimum [Member] Variable Annuity [Member]	Dec. 31, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Maximum [Member] Variable Annuity [Member]	Feb. 04, 2013 Berkshire Hathway Life Insurance Company Of Nebraska [Member] Maximum [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]	Dec. 31, 2013 Other Retrocessionaires [Member] Variable Annuity [Member] Guaranteed Minimum Income Benefit [Member]
Ceded Credit Risk [Line Items]
Pre Tax Guaranteed Benefits Reserve Strengthening							$ 43,000,000	$ 70,000,000							$ 700,000,000
After Tax Guaranteed Benefits Reserve Strengthening							27,000,000	45,000,000							500,000,000
Ceded Reinsurance Agreement, Coverage Limit, Fixed Portion																			3,800,000,000
Ceded Reinsurance Agreement, Coverage Limit, Variable Portion																	100,000,000	300,000,000
Ceded Reinsurace Agreement, Covered Claims, Expected Amount														4,000,000,000
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	2,196,000,000	0	0										2,200,000,000		1,600,000,000
Ceded Reinsurance Agreement, Cost Of Reinsurance														700,000,000
Derivative Gain (Loss)										(32,000,000)	(105,000,000)	(14,000,000)
Guaranteed Minimum Income Benefits Assets									1,300,000,000							352,000,000							399,000,000
Combined GMDB recoverables and GMIB assets						$ 2,100,000,000								$ 1,600,000,000
Combined GMDB recoverables and GMIB assets percent secured						90.00%
Ceded Credit Risk Number Of External Reinsurers				3	2																		2