Business Segments (Information by Operating Segment) (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Operating Revenues	$ 629,579	$ 621,638	$ 628,933	$ 601,740	$ 616,367	$ 641,432	$ 680,890	$ 647,425	$ 2,481,890	$ 2,586,114	$ 2,737,032
Income (loss) from operations	109,489	68,033	74,140	51,872	67,811	(213,723)	56,225	8,862	303,534	(80,825)	232,720
Equity in (losses) earnings of affiliates, net	(7,042)	(1,008)	(891)	1,004	(35)	95	(353)	(404)	(7,937)	(697)	100,370
Interest expense, net									(32,297)	(30,745)	(33,397)
Other (expense) income, net	(28,513)	(18,225)	19,000	15,096	21,262	(40,458)	11,678	(1,105)	(12,642)	(8,623)	778,010
Income (Loss) from Continuing Operations Before Income Taxes	64,118	40,926	84,999	60,615	81,609	(261,435)	59,525	(589)	250,658	(120,890)	1,077,703
Depreciation of property, plant and equipment	15,717	16,097	16,045	16,761	15,640	14,460	25,609	22,197	64,620	77,906	74,913
Amortization of intangible assets and impairment of goodwill and other long-lived assets									28,274	278,717	35,489
Amortization of intangible assets	7,511	$ 6,620	$ 6,278	$ 6,262	5,120	4,512	4,647	4,738	26,671	19,017	18,187
Impairment of goodwill and other long-lived assets					4,233	$ 248,591	$ 6,876	$ 0	1,603	259,700	17,302
Net Pension (Credit) Expense									(67,097)	(60,557)	(64,780)
Capital expenditures									70,712	62,033	57,007
Identifiable Assets	3,068,042				2,963,063				3,068,042	2,963,063
Investments in Marketable equity securities	424,229				350,563				424,229	350,563
Investments in Affiliates	58,806				59,229				58,806	59,229
Prepaid Pension Cost	881,593				979,970				881,593	979,970
Total Assets	4,432,670				4,352,825				4,432,670	4,352,825
Operating Segments [Member] | Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues									1,598,461	1,927,521	2,160,417
Income (loss) from operations									93,632	(223,456)	65,463
Depreciation of property, plant and equipment									41,187	61,177	61,737
Amortization of intangible assets and impairment of goodwill and other long-lived assets									7,516	262,353	24,941
Amortization of intangible assets									7,516	5,523	7,738
Impairment of goodwill and other long-lived assets									0	256,830	17,203
Net Pension (Credit) Expense									11,803	18,804	15,418
Capital expenditures									26,497	42,220	33,528
Identifiable Assets	1,479,267				1,454,520				1,479,267	1,454,520
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Higher Education [Member]
Segment Reporting Information [Line Items]
Operating Revenues									617,047	849,625	1,010,058
Income (loss) from operations									66,632	55,572	83,069
Depreciation of property, plant and equipment									16,822	17,937	29,187
Net Pension (Credit) Expense									7,620	10,849	10,514
Capital expenditures									5,364	10,202	11,551
Identifiable Assets	373,127				447,282				373,127	447,282
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Test Preparation [Member]
Segment Reporting Information [Line Items]
Operating Revenues									286,556	301,607	304,662
Income (loss) from operations									9,599	16,798	(4,730)
Depreciation of property, plant and equipment									6,287	9,045	12,547
Net Pension (Credit) Expense									3,072	3,101	2,888
Capital expenditures									4,672	8,720	1,143
Identifiable Assets	133,709				134,535				133,709	134,535
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan International [Member]
Segment Reporting Information [Line Items]
Operating Revenues									696,362	770,273	840,915
Income (loss) from operations									48,398	53,661	69,153
Depreciation of property, plant and equipment									17,523	17,811	19,297
Net Pension (Credit) Expense									268	424	356
Capital expenditures									16,252	22,673	20,802
Identifiable Assets	950,922				826,475				950,922	826,475
Operating Segments [Member] | Education [Member] | Reportable Subsegments [Member] | Kaplan Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues									214	6,502	6,094
Income (loss) from operations									(30,968)	(349,583)	(82,034)
Depreciation of property, plant and equipment									555	16,384	706
Net Pension (Credit) Expense									843	4,430	1,660
Capital expenditures									209	625	32
Identifiable Assets	21,509				46,228				21,509	46,228
Operating Segments [Member] | Education [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(1,718)	(486)	(1,312)
Income (loss) from operations									(29)	96	5
Operating Segments [Member] | Television Broadcasting [Member]
Segment Reporting Information [Line Items]
Operating Revenues									409,718	359,192	363,836
Income (loss) from operations									200,470	164,927	187,833
Depreciation of property, plant and equipment									9,942	9,551	8,409
Amortization of intangible assets and impairment of goodwill and other long-lived assets									251	252	32
Net Pension (Credit) Expense									1,714	1,620	1,355
Capital expenditures									27,453	9,998	11,295
Identifiable Assets	336,631				312,243				336,631	312,243
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									473,850	299,517	212,907
Income (loss) from operations									(22,102)	(13,667)	(21,086)
Depreciation of property, plant and equipment									12,375	6,168	3,931
Amortization of intangible assets and impairment of goodwill and other long-lived assets									20,507	16,112	10,516
Net Pension (Credit) Expense									1,118	964	748
Capital expenditures									16,047	9,504	5,110
Identifiable Assets	796,935				712,161				796,935	712,161
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Income (loss) from operations									31,534	(8,629)	510
Depreciation of property, plant and equipment									1,116	1,010	836
Amortization of intangible assets and impairment of goodwill and other long-lived assets									0	0	0
Net Pension (Credit) Expense									(81,732)	(81,945)	(82,301)
Capital expenditures									715	311	7,074
Identifiable Assets	$ 455,209				$ 484,139				455,209	484,139
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Operating Revenues									$ (139)	$ (116)	$ (128)