Pension and Postretirement Plans (Narrative) (Details) (USD $)	12 Months Ended																																					12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Jan. 02, 2011	Dec. 31, 2012 Pension Plans [Member] companies	Dec. 31, 2011 Pension Plans [Member]	Jan. 02, 2011 Pension Plans [Member]	Jan. 02, 2011 Pension Plans [Member] Newsweek [Member]	Dec. 31, 2012 Pension Plans [Member] Washington Post Newspaper [Member]	Dec. 31, 2011 Pension Plans [Member] Robinson Terminal Warehouse and Washington Post Newspaper [Member]	Dec. 31, 2012 Pension Plans [Member] Post-Newsweek Media [Member]	Dec. 31, 2012 Multiemployer Pension Plans [Member]	Dec. 31, 2011 Multiemployer Pension Plans [Member]	Jan. 02, 2011 Multiemployer Pension Plans [Member]	Dec. 31, 2011 Multiemployer Pension Plans [Member] CWA/ITU Negotiated Pension Plan [Member]	Jan. 02, 2011 Multiemployer Pension Plans [Member] CWA/ITU Negotiated Pension Plan [Member]	Dec. 31, 2012 Multiemployer Pension Plans [Member] Other individually insignificant multiemployer pension plans [Member]	Dec. 31, 2011 Multiemployer Pension Plans [Member] Other individually insignificant multiemployer pension plans [Member]	Jan. 02, 2011 Multiemployer Pension Plans [Member] Other individually insignificant multiemployer pension plans [Member]	Jan. 02, 2011 Multiemployer Pension Plans [Member] Washington Post Newspaper [Member] CWA/ITU Negotiated Pension Plan [Member]	Dec. 31, 2010 Multiemployer Pension Plans [Member] Washington Post Newspaper [Member] CWA/ITU Negotiated Pension Plan [Member]	Dec. 31, 2011 Multiemployer Pension Plans [Member] Daily Herald [Member] CWA/ITU Negotiated Pension Plan [Member]	Dec. 31, 2012 Multiemployer Pension Plans [Member] Daily Herald [Member] GCIU Employer's Trust Fund [Member]	Dec. 31, 2012 Supplemental Executive Retirement Plan (SERP) [Member]	Dec. 31, 2011 Supplemental Executive Retirement Plan (SERP) [Member]	Dec. 31, 2012 Other Postretirement Plans [Member]	Dec. 31, 2011 Other Postretirement Plans [Member]	Jan. 02, 2011 Other Postretirement Plans [Member]	Dec. 31, 2012 Other Postretirement Plans [Member] Pre-Age 65 [Member]	Dec. 31, 2012 Other Postretirement Plans [Member] Post-Age 65 MA-PD Plan [Member]	Dec. 31, 2012 Other Postretirement Plans [Member] Post-Age 65 Non MA-PD Plan [Member]	Jan. 02, 2011 Other Postretirement Plans [Member] Newsweek [Member]	Dec. 31, 2012 Other Postretirement Plans [Member] Washington Post Newspaper [Member]	Dec. 31, 2012 Savings Plan [Member]	Dec. 31, 2011 Savings Plan [Member]	Jan. 02, 2011 Savings Plan [Member]	Dec. 31, 2012 Berkshire Hathaway Common Stock [Member] Pension Plans [Member]	Dec. 31, 2011 Berkshire Hathaway Common Stock [Member] Pension Plans [Member]	Dec. 31, 2012 Foreign Investments [Member] Pension Plans [Member]	Dec. 31, 2012 Single Equity Concentration [Member] Pension Plans [Member] investment	Dec. 31, 2011 Single Equity Concentration [Member] Pension Plans [Member] investment	Dec. 31, 2012 Concentration In Single Entity, Type Of Industry, Foreign Country Or Individual Fund [Member] Pension Plans [Member]	Dec. 31, 2012 Fixed income securities [Member] Pension Plans [Member]	Dec. 31, 2012 Geographic Concentration [Member] Foreign Investments [Member] Pension Plans [Member] country	Dec. 31, 2011 Geographic Concentration [Member] Foreign Investments [Member] Pension Plans [Member] country
Retirement Benefits Disclosure [Line Items]
Early retirement program expense	$ 8,508,000	$ 634,000	$ 0	$ 8,508,000	$ 634,000	$ 0		$ 7,500,000	$ 600,000	$ 1,000,000
Special termination benefits				0	0	5,295,000	5,300,000
Recognition Of Prior Service Cost Related To Dispositions Including Discontinued Operations				0	0	2,369,000	2,400,000
Accumulated benefit obligation				1,349,200,000	1,191,900,000																		97,600,000	86,600,000
Defined Benefit Plan, Contributions by Employer				0	0	0																	3,681,000	3,114,000	3,337,000	2,286,000
Estimated employer contributions in next fiscal year				0
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 the company				None
Curtailment gain																									438,000	0	(8,583,000)				8,500,000	400,000
Discount rate to determine benefit obligation																									3.30%	3.90%
Assumed health care cost trend rate																												8.00%	21.80%	7.00%
Direction of change for assumed health care cost trend rate																												decreasing	decreasing	decreasing
Ultimate health care cost trend rate																												5.00%	5.00%	5.00%
Year that rate reaches ultimate trend rate																												2025	2023	2021
Discount rate to determine periodic cost																									3.90%	4.60%	5.25%
Contributions to multiemployer pension plans											200,000	400,000	1,000,000	100,000	600,000	200,000	300,000	400,000
Value of investments																																				179,900,000	154,000,000		223,100,000	222,400,000			240,400,000	241,400,000
Percentage of total plan assets																																							11.00%	12.00%			12.00%	13.00%
Multiemployer pension plan withdrawal charge	886,000	2,415,000	20,355,000																20,400,000		2,400,000	900,000
Expense associated with the retirement benefits provided under incentive savings plans																																	$ 17,300,000	$ 20,400,000	$ 18,900,000
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
Percentage of total contribution by the Company																				more than 5%