Business Segments (Information by Operating Segment) (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended					12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Operating Revenues	$ 840,561	$ 871,635	$ 858,954	$ 870,504	$ 820,592	$ 3,421,685	$ 3,384,550
Income (Loss) from Operations	79,529	97,617	78,416	96,301	47,147	319,481	149,669
Equity in earnings of affiliates, net	4,052	37	5,892	3,868	3,418	13,215	14,086
Interest Expense, Net	(8,221)	(8,248)	(8,579)	(8,526)	(8,450)	(33,803)	(32,551)
Other Income (Expense), Net	133,273	(14,920)	8,110	(12,858)	(4,083)	(23,751)	(5,456)
Income from Continuing Operations Before Income Taxes	208,633	74,486	83,839	78,785	38,032	275,142	125,748
Depreciation of property, plant and equipment	53,245	58,954	54,705	56,879	58,959	229,497	240,313
Amortization of intangible assets and impairment of goodwill and other long-lived assets	3,081	6,981	2,837	3,313	3,717	16,848	132,539
Amortization of intangible assets	3,081	3,731	2,837	3,313	3,717	13,598	20,946
Impairment of goodwill and other long-lived assets		3,250	0	0	0	3,250	111,593
Net Pension (Credit) Expense	(12,188)	(9,058)	(2,687)	(2,601)	(2,673)	(17,019)	(8,532)
Identifiable Assets	4,024,545	4,062,631				4,062,631
Investment in Marketable Equity Securities	510,697	487,156				487,156
Investments in Affiliates	20,953	15,754				15,754
Prepaid Pension Cost	1,250,658	1,245,505				1,245,505
Assets Held for Sale	113,709	0				0
Total Assets	5,920,562	5,811,046				5,811,046
Operating Segments [Member] | Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues	526,174	555,011	546,452	548,230	527,815	2,177,508	2,196,496
Income (Loss) from Operations	2,522	14,596	17,035	23,726	(4,056)	51,301	(105,368)
Depreciation of property, plant and equipment	16,444	28,134	18,978	20,064	22,588	89,764	101,183
Amortization of intangible assets and impairment of goodwill and other long-lived assets	2,288	6,044	2,287	2,363	2,518	13,212	129,312
Amortization of intangible assets	2,288				2,518
Net Pension (Credit) Expense	4,143	4,032	4,169	4,231	4,106	16,538	11,584
Identifiable Assets	1,745,562	1,921,037				1,921,037
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Higher Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues	253,779				271,860
Income (Loss) from Operations	13,144				5,101
Depreciation of property, plant and equipment	7,740				13,439
Net Pension (Credit) Expense	2,628				2,807
Identifiable Assets	653,409	859,208				859,208
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Test Preparation [Member]
Segment Reporting Information [Line Items]
Operating Revenues	67,804				68,943
Income (Loss) from Operations	(6,628)				(4,345)
Depreciation of property, plant and equipment	3,784				4,758
Net Pension (Credit) Expense	722				640
Identifiable Assets	177,288	173,435				173,435
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan International [Member]
Segment Reporting Information [Line Items]
Operating Revenues	202,867				184,813
Income (Loss) from Operations	10,882				6,397
Depreciation of property, plant and equipment	4,708				3,996
Net Pension (Credit) Expense	89				87
Identifiable Assets	866,656	864,507				864,507
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	2,014				2,604
Income (Loss) from Operations	(14,920)				(11,340)
Depreciation of property, plant and equipment	212				395
Net Pension (Credit) Expense	704				572
Identifiable Assets	48,209	23,887				23,887
Operating Segments [Member] | Education [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(290)				(405)
Income (Loss) from Operations	44				131
Operating Segments [Member] | Cable [Member]
Segment Reporting Information [Line Items]
Operating Revenues	203,921	200,240	202,381	204,550	200,138	807,309	787,117
Income (Loss) from Operations	41,162	48,697	39,715	44,710	36,613	169,735	154,581
Depreciation of property, plant and equipment	33,787	27,541	32,946	33,964	33,733	128,184	129,107
Amortization of intangible assets and impairment of goodwill and other long-lived assets	35	52	61	57	50	220	211
Net Pension (Credit) Expense	864	940	973	913	882	3,708	2,540
Identifiable Assets	1,183,434	1,215,320				1,215,320
Operating Segments [Member] | Television Broadcasting [Member]
Segment Reporting Information [Line Items]
Operating Revenues	85,651	85,688	73,488	80,228	68,902	308,306	328,396
Income (Loss) from Operations	44,386	43,999	32,847	39,235	29,111	145,192	162,131
Depreciation of property, plant and equipment	1,994	2,142	2,181	2,214	2,209	8,746	9,253
Amortization of intangible assets and impairment of goodwill and other long-lived assets	0	0	0	0	0	0	0
Net Pension (Credit) Expense	320	70	1,297	1,250	1,344	3,961	5,046
Identifiable Assets	291,518	383,251				383,251
Operating Segments [Member] | Other Businesses [Member]
Segment Reporting Information [Line Items]
Operating Revenues	24,913	30,735	36,682	37,572	23,814	128,803	72,837
Income (Loss) from Operations	(10,747)	(3,912)	(5,046)	(5,968)	(8,542)	(23,468)	(33,010)
Depreciation of property, plant and equipment	520	616	555	577	429	2,177	770
Amortization of intangible assets and impairment of goodwill and other long-lived assets	758	885	489	893	1,149	3,416	3,016
Net Pension (Credit) Expense	164	187	173	134	116	610	169
Identifiable Assets	156,858	171,539				171,539
Operating Segments [Member] | Corporate Office [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0	0	0	0
Income (Loss) from Operations	2,206	(5,763)	(6,135)	(5,402)	(5,979)	(23,279)	(28,665)
Depreciation of property, plant and equipment	500	521	45	60	0	626	0
Amortization of intangible assets and impairment of goodwill and other long-lived assets	0	0	0	0	0	0	0
Net Pension (Credit) Expense	(17,679)	(14,287)	(9,299)	(9,129)	(9,121)	(41,836)	(27,871)
Identifiable Assets	647,173	371,484				371,484
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Operating Revenues	$ (98)	$ (39)	$ (49)	$ (76)	$ (77)	$ (241)	$ (296)