Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Assets
Marketable equity securities	$ 184,915		$ 193,793
7.25% Unsecured Notes due February 1, 2019 [Member]
Liabilities:
7.25% unsecured notes	451,300		450,300
Fair Value, Measurements, Recurring [Member]
Assets
Money market investments	227,485	[1]	368,131	[1]
Commercial paper	221,962	[2]	226,197	[2]
Marketable equity securities	184,915	[3]	193,793	[3]
Other current investments	30,065	[4]	32,959	[4]
Total Financial Assets	664,427		821,080
Liabilities:
Deferred compensation plan liabilities	69,836	[5]	70,661	[5]
Interest rate swap			179	[6]
Total Financial Liabilities	521,092		562,111
Fair Value, Measurements, Recurring [Member] | 7.25% Unsecured Notes due February 1, 2019 [Member]
Liabilities:
7.25% unsecured notes	451,256	[7]	450,344	[7]
Fair Value, Measurements, Recurring [Member] | AUD $50 million portion of Revolver [Member]
Liabilities:
AUD Revolving credit borrowing			40,927	[7]
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Money market investments	0	[1]	0	[1]
Commercial paper	221,962	[2]	226,197	[2]
Marketable equity securities	184,915	[3]	193,793	[3]
Other current investments	9,917	[4]	11,788	[4]
Total Financial Assets	416,794		431,778
Liabilities:
Deferred compensation plan liabilities	0	[5]	0	[5]
Interest rate swap			0	[6]
Total Financial Liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | 7.25% Unsecured Notes due February 1, 2019 [Member]
Liabilities:
7.25% unsecured notes	0	[7]	0	[7]
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | AUD $50 million portion of Revolver [Member]
Liabilities:
AUD Revolving credit borrowing			0	[7]
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Money market investments	227,485	[1]	368,131	[1]
Commercial paper	0	[2]	0	[2]
Marketable equity securities	0	[3]	0	[3]
Other current investments	20,148	[4]	21,171	[4]
Total Financial Assets	247,633		389,302
Liabilities:
Deferred compensation plan liabilities	69,836	[5]	70,661	[5]
Interest rate swap			179	[6]
Total Financial Liabilities	521,092		562,111
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | 7.25% Unsecured Notes due February 1, 2019 [Member]
Liabilities:
7.25% unsecured notes	451,256	[7]	450,344	[7]
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | AUD $50 million portion of Revolver [Member]
Liabilities:
AUD Revolving credit borrowing			$ 40,927	[7]

[1] The Company’s money market investments are included in cash, cash equivalents and restricted cash.

[2] The Company's commercial paper investments with original maturities of 90 days or less are included in cash and cash equivalents.

[3] The Company’s investments in marketable equity securities are classified as available-for-sale.

[4] Includes U.S. Government Securities, corporate bonds, mutual funds and time deposits.

[5] Includes Graham Holdings Company's Deferred Compensation Plan and supplemental savings plan benefits under the Graham Holdings Company's Supplemental Executive Retirement Plan, which are included in accrued compensation and related benefits. These plans measure the market value of a participant's balance in a notional investment account that is comprised primarily of mutual funds, which are based on observable market prices. However, since the deferred compensation obligations are not exchanged in an active market, they are classified as Level 2 in the fair value hierarchy. Realized and unrealized gains (losses) on deferred compensation are included in operating income.

[6] Included in Other liabilities. The Company utilized a market approach model using the notional amount of the interest rate swap multiplied by the observable inputs of time to maturity and market interest rates.

[7] See Note 6 for carrying amount of these notes and borrowing. The fair value of long-term debt is determined based on a number of observable inputs, including the current market activity of the Company’s publicly traded notes, trends in investor demands and market values of comparable publicly traded debt.