Pension and Postretirement Plans (Narrative) (Details) (USD $)	3 Months Ended					12 Months Ended		3 Months Ended			3 Months Ended				6 Months Ended	3 Months Ended												3 Months Ended		3 Months Ended			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014 Pension Plan [Member] companies	Mar. 31, 2013 Pension Plan [Member]	Dec. 31, 2013 Pension Plan [Member]	Mar. 31, 2014 Pension Plan [Member] Discontinued Operations [Member]	Mar. 31, 2013 Pension Plan [Member] Discontinued Operations [Member]	Jun. 30, 2013 Pension Plan [Member] Washington Post Newspaper [Member] Voluntary Retirement Incentive Program [Member] Discontinued Operations [Member]	Mar. 31, 2013 Pension Plan [Member] Washington Post Newspaper [Member] Voluntary Retirement Incentive Program [Member] Discontinued Operations [Member]	Jun. 30, 2013 Pension Plan [Member] Washington Post Newspaper [Member] Voluntary Retirement Incentive Program [Member] Discontinued Operations [Member]	Mar. 31, 2013 Pension Plan [Member] Washington Post Newspaper [Member] Special Separation Benefits [Member] Discontinued Operations [Member]	Mar. 31, 2014 Pension Plan [Member] Corporate Office [Member] Separation Incentive Program [Member]	Mar. 31, 2014 Supplemental Executive Retirement Plan (SERP) [Member]	Mar. 31, 2013 Supplemental Executive Retirement Plan (SERP) [Member]	Mar. 31, 2014 Supplemental Executive Retirement Plan (SERP) [Member] Discontinued Operations [Member]	Mar. 31, 2013 Supplemental Executive Retirement Plan (SERP) [Member] Discontinued Operations [Member]	Mar. 31, 2014 Other Postretirement Plans [Member]	Mar. 31, 2013 Other Postretirement Plans [Member]	Mar. 31, 2013 Other Postretirement Plans [Member] Discontinued Operations [Member]	Mar. 31, 2013 Other Postretirement Plans [Member] Daily Herald [Member] Discontinued Operations [Member]	Mar. 31, 2014 Berkshire Hathaway Common Stock [Member] Pension Plan [Member]	Dec. 31, 2013 Berkshire Hathaway Common Stock [Member] Pension Plan [Member]	Mar. 31, 2014 Single Equity Concentration [Member] Pension Plan [Member] Investment	Dec. 31, 2013 Single Equity Concentration [Member] Pension Plan [Member]	Mar. 31, 2014 Foreign Investments [Member] Pension Plan [Member]	Mar. 31, 2014 Fixed income securities [Member] Pension Plan [Member]	Dec. 31, 2013 Single Equity Concentration [Member] Pension Plan [Member] Investment	Mar. 31, 2014 Concentration In Single Entity, Type Of Industry, Foreign Country Or Individual Fund [Member] Defined Benefit Plan Assets Total [Member] Pension Plan [Member]	Mar. 31, 2014 Geographic Concentration [Member] Foreign Investments [Member] Pension Plan [Member] campus	Dec. 31, 2013 Geographic Concentration [Member] Foreign Investments [Member] Pension Plan [Member] country
Retirement Benefits Disclosure [Line Items]
Total Cost (Benefit)	$ (12,188,000)	$ (9,058,000)	$ (2,687,000)	$ (2,601,000)	$ (2,673,000)	$ (17,019,000)	$ (8,532,000)	$ (12,110,000)	$ 18,648,000		$ 100,000	$ 7,100,000						$ 1,845,000	$ 2,177,000	$ 100,000	$ 300,000	$ 22,000	$ (4,135,000)	$ 600,000
Early retirement program expense	4,490,000				14,258,000			4,490,000	14,258,000				8,400,000	12,000,000	20,400,000	2,300,000	4,500,000
Number of investment companies actively managing plan assets								2
Defined benefit plan, target allocation maximum percentage of assets, equity securities																														24.00%
Defined benefit plan, target allocation maximum percentage of assets, singular equity security, without prior approval by plan administrator																										20.00%		10.00%
Defined benefit plan, target allocation percentage of assets, fixed-income securities, range minimum																															10.00%
Minimum percentage of plan assets considered as significant concentrations in pension plans																																	10.00%
Amount of plan assets managed internally by company								0
Settlement gain																									3,500,000
Value of investments																												429,100,000	382,100,000					447,000,000	398,900,000
Percentage of total plan assets								100.00%		100.00%																		18.00%	16.00%					19.00%	17.00%
Value of related party investments																										$ 219,500,000	$ 208,400,000
Number of investments the company's pension plan held which individually exceed 10% of total plan assets																												1				1
Number of foreign countries for which the companys pension plan holds investments that exceed 10% of total plan assets																																		1	1