Business Segments (Information by Operating Segment) (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Operating Revenues	$ 846,148	$ 836,541
Income (Loss) from Operations	46,555	78,869
Equity in (losses) earnings of affiliates, net	(404)	4,052
Interest Expense, Net	(7,962)	(8,221)
Other (Expense) Income, Net	(1,105)	133,273
Income from Continuing Operations Before Income Taxes	37,084	207,973
Depreciation of property, plant and equipment	58,545	53,217
Amortization of intangible assets	4,769	2,717
Net Pension (Credit) Expense	(11,432)	(12,188)
Identifiable Assets	4,088,911		4,384,167
Investment in Marketable Equity Securities	184,915		193,793
Investments in Affiliates	36,120		19,811
Prepaid Pension Cost	1,164,001		1,152,488
Assets Held for Sale	51,443		2,060
Total Assets	5,525,390		5,752,319
Operating Segments [Member] | Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues	500,602	522,154
Income (Loss) from Operations	(22,849)	1,862
Depreciation of property, plant and equipment	18,528	16,416
Amortization of intangible assets	1,507	1,924
Net Pension (Credit) Expense	3,947	4,143
Identifiable Assets	1,535,949		1,781,543
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Higher Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues	237,568	253,779
Income (Loss) from Operations	593	13,144
Depreciation of property, plant and equipment	4,828	7,740
Net Pension (Credit) Expense	2,532	2,628
Identifiable Assets	557,851		749,421
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Test Preparation [Member]
Segment Reporting Information [Line Items]
Operating Revenues	69,226	67,804
Income (Loss) from Operations	(4,334)	(6,628)
Depreciation of property, plant and equipment	2,890	3,784
Net Pension (Credit) Expense	775	722
Identifiable Assets	169,493		167,055
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan International [Member]
Segment Reporting Information [Line Items]
Operating Revenues	192,081	198,847
Income (Loss) from Operations	7,717	9,858
Depreciation of property, plant and equipment	4,654	4,680
Net Pension (Credit) Expense	106	89
Identifiable Assets	776,129		838,148
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	1,859	2,014
Income (Loss) from Operations	(26,857)	(14,556)
Depreciation of property, plant and equipment	6,156	212
Net Pension (Credit) Expense	534	704
Identifiable Assets	32,476		26,919
Operating Segments [Member] | Education [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(132)	(290)
Income (Loss) from Operations	32	44
Operating Segments [Member] | Cable [Member]
Segment Reporting Information [Line Items]
Operating Revenues	198,723	203,921
Income (Loss) from Operations	39,076	41,162
Depreciation of property, plant and equipment	36,348	33,787
Amortization of intangible assets	31	35
Net Pension (Credit) Expense	975	864
Identifiable Assets	1,254,511		1,253,764
Operating Segments [Member] | Television Broadcasting [Member]
Segment Reporting Information [Line Items]
Operating Revenues	83,564	85,651
Income (Loss) from Operations	38,562	44,386
Depreciation of property, plant and equipment	2,109	1,994
Amortization of intangible assets	63	0
Net Pension (Credit) Expense	391	320
Identifiable Assets	299,983		305,426
Operating Segments [Member] | Other Businesses [Member]
Segment Reporting Information [Line Items]
Operating Revenues	63,259	24,913
Income (Loss) from Operations	(5,162)	(10,747)
Depreciation of property, plant and equipment	1,302	520
Amortization of intangible assets	3,168	758
Net Pension (Credit) Expense	193	164
Identifiable Assets	488,748		518,807
Operating Segments [Member] | Corporate Office [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Income (Loss) from Operations	(3,072)	2,206
Depreciation of property, plant and equipment	258	500
Amortization of intangible assets	0	0
Net Pension (Credit) Expense	(16,938)	(17,679)
Identifiable Assets	509,720		524,627
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Operating Revenues	$ 0	$ (98)