Business Segments (Information by Operating Segment) (Details 1) - USD ($) $ in Thousands	3 Months Ended							9 Months Ended		12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Operating Revenues	$ 641,432	$ 680,890	$ 647,425	$ 727,625	$ 703,205	$ 673,582	$ 632,620	$ 1,969,747	$ 2,009,407	$ 2,737,032	$ 2,600,602
Income (Loss) from Operations	(213,723)	56,225	8,862	99,024	41,209	54,780	37,707	(148,636)	133,695	232,720	149,434
Equity in earnings (losses) of affiliates, net	95	(353)	(404)	202	4,613	91,503	4,052	(662)	100,168	100,370	13,215
Interest Expense, Net	(7,349)	(8,025)	(7,942)	(8,555)	(8,769)	(7,884)	(8,189)	(23,316)	(24,841)	(33,397)	(33,667)
Other income (expense), net	(40,458)	11,678	(1,105)	387,346	(10,723)	268,114	133,273	(29,885)	390,664	778,010	(23,751)
Income (loss) from Continuing Operations Before Income Taxes	(261,435)	59,525	(589)	478,017	26,330	406,513	166,843	(202,499)	599,686	1,077,703	105,231
Depreciation of property, plant and equipment	14,460	25,609	22,197	18,618	18,664	18,201	19,430	62,266	56,295	74,913	101,171
Amortization Of Intangible Assets And Impairment Of Goodwill And Other Long-Lived Assets	253,103	11,523	4,738					269,364	12,972	35,489	15,169
Amortization Of Intangible Assets And Impairment Of Intangibles And Other Long-Lived Assets				22,517	7,354	2,936	2,682
Amortization of intangible assets	4,512	4,647	4,738	5,215	7,354	2,936	2,682	13,897	12,972	18,187	11,919
Impairment of Goodwill and Other Long-lived Assets	248,591				0			255,467	0
Net Pension (Credit) Expense	(16,255)	(12,415)	(12,407)	(18,686)	(14,237)	(18,807)	(13,052)	(41,077)	(46,095)	(64,780)	(20,727)
Identifiable Assets	2,969,058			4,384,167				2,969,058		4,384,167
Investments in Marketable Equity Securities	312,892			193,793				312,892		193,793
Investments in Affiliates	53,198			19,811				53,198		19,811
Prepaid Pension Cost	1,189,181			1,152,488				1,189,181		1,152,488
Assets Held for Sale	0			2,060				0		2,060
Total Assets	4,524,329			5,752,319				4,524,329		5,752,319
Operating Segments [Member] | Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues	481,746	523,625	500,602	551,381	543,918	542,964	522,154	1,505,973	1,609,036	2,160,417	2,163,734
Income (Loss) from Operations	(242,777)	15,848	(22,849)	33,413	12,551	17,637	1,862	(249,778)	32,050	65,463	50,989
Depreciation of property, plant and equipment	10,637	21,980	18,528	14,713	15,237	15,372	16,416	51,145	47,024	61,737	89,622
Amortization Of Intangible Assets And Impairment Of Goodwill And Other Long-Lived Assets	249,930	8,343	1,507					259,780	5,649	24,941	11,753
Amortization Of Intangible Assets And Impairment Of Intangibles And Other Long-Lived Assets				19,292	1,927	1,798	1,924
Amortization of intangible assets	1,339				1,927			4,313	5,649
Impairment of Goodwill and Other Long-lived Assets	248,591				0			255,467	0
Net Pension (Credit) Expense	7,525	3,947	3,947	3,855	3,854	3,566	4,143	15,419	11,563	15,418	16,538
Identifiable Assets	1,249,359			1,781,543				1,249,359		1,781,543
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Higher Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues	203,529				249,882			681,814	755,597
Income (Loss) from Operations	3,153				5,391			28,510	39,487
Depreciation of property, plant and equipment	4,066				7,320			13,688	22,140
Net Pension (Credit) Expense	3,964				2,628			9,028	7,885
Identifiable Assets	227,406			749,421				227,406		749,421
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Test Preparation [Member]
Segment Reporting Information [Line Items]
Operating Revenues	83,706				85,108			233,313	234,010
Income (Loss) from Operations	13,620				6,980			16,365	(3,552)
Depreciation of property, plant and equipment	2,052				2,865			7,205	9,721
Net Pension (Credit) Expense	775				722			2,325	2,166
Identifiable Assets	147,998			167,055				147,998		167,055
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan International [Member]
Segment Reporting Information [Line Items]
Operating Revenues	192,702				207,615			585,486	615,507
Income (Loss) from Operations	8,295				13,853			33,585	40,609
Depreciation of property, plant and equipment	4,277				4,951			14,004	14,546
Net Pension (Credit) Expense	114				89			326	267
Identifiable Assets	811,672			838,148				811,672		838,148
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	1,905				1,492			5,723	4,891
Income (Loss) from Operations	(267,882)				(13,651)			(328,333)	(44,608)
Depreciation of property, plant and equipment	242				101			16,248	617
Net Pension (Credit) Expense	2,672				415			3,740	1,245
Identifiable Assets	62,283			26,919				62,283		26,919
Operating Segments [Member] | Education [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(96)				(179)			(363)	(969)
Income (Loss) from Operations	37				(22)			95	114
Operating Segments [Member] | Television Broadcasting [Member]
Segment Reporting Information [Line Items]
Operating Revenues	89,693	90,753	83,564	102,446	87,442	88,297	85,651	264,010	261,390	363,836	308,306
Income (Loss) from Operations	40,526	42,014	38,562	54,380	44,979	44,088	44,386	121,102	133,452	187,833	145,192
Depreciation of property, plant and equipment	2,237	2,125	2,109	2,228	2,148	2,039	1,994	6,471	6,181	8,409	8,746
Amortization Of Intangible Assets And Impairment Of Goodwill And Other Long-Lived Assets	63	63	63					189	0	32	0
Amortization Of Intangible Assets And Impairment Of Intangibles And Other Long-Lived Assets				32	0	0	0
Net Pension (Credit) Expense	425	391	391	338	338	358	320	1,207	1,016	1,355	3,961
Identifiable Assets	309,232			305,426				309,232		305,426
Operating Segments [Member] | Other Businesses [Member]
Segment Reporting Information [Line Items]
Operating Revenues	70,052	66,512	63,259	73,798	71,845	42,351	24,913	199,823	139,109	212,907	128,803
Income (Loss) from Operations	(3,059)	(2,161)	(5,162)	5,948	(9,292)	(6,995)	(10,747)	(10,382)	(27,034)	(21,086)	(23,468)
Depreciation of property, plant and equipment	1,335	1,254	1,302	1,430	1,201	780	520	3,891	2,501	3,931	2,177
Amortization Of Intangible Assets And Impairment Of Goodwill And Other Long-Lived Assets	3,110	3,117	3,168					9,395	7,323	10,516	3,416
Amortization Of Intangible Assets And Impairment Of Intangibles And Other Long-Lived Assets				3,193	5,427	1,138	758
Net Pension (Credit) Expense	328	186	193	191	191	202	164	707	557	748	610
Identifiable Assets	472,272			518,807				472,272		518,807
Operating Segments [Member] | Corporate Office [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0	0	0	0	0	0	0	0
Income (Loss) from Operations	(8,413)	524	(1,689)	5,283	(7,029)	50	2,206	(9,578)	(4,773)	510	(23,279)
Depreciation of property, plant and equipment	251	250	258	247	78	10	500	759	589	836	626
Amortization Of Intangible Assets And Impairment Of Goodwill And Other Long-Lived Assets	0	0	0					0	0	0	0
Amortization Of Intangible Assets And Impairment Of Intangibles And Other Long-Lived Assets				0	0	0	0
Net Pension (Credit) Expense	(24,533)	(16,939)	(16,938)	(23,070)	(18,620)	(22,933)	(17,679)	(58,410)	(59,231)	(82,301)	(41,836)
Identifiable Assets	938,195			1,778,391				938,195		1,778,391
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Operating Revenues	$ (59)	$ 0	$ 0	$ 0	$ 0	$ (30)	$ (98)	$ (59)	$ (128)	$ (128)	$ (241)