Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 30, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net revenue	$ 215,954	$ 193,393	$ 174,726	$ 194,127	$ 189,973	$ 175,056	$ 158,594	$ 167,432	$ 778,200	$ 691,055	$ 598,335
Costs and expenses:
Instructional costs and services	92,427	83,180	75,357	78,687	78,552	71,714	67,847	70,678	329,651	288,791	254,419
Admissions advisory and related, including $1,575 in 2015; $2,974 in 2014; and $3,412 in 2013, respectively, to related parties	29,361	27,506	27,372	28,333	28,774	27,324	26,208	26,261	112,572	108,567	97,077
Advertising	18,419	19,360	18,419	20,031	16,854	16,491	15,751	16,712	76,229	65,808	60,985
Marketing and promotional	1,978	1,827	1,788	1,694	1,810	1,931	1,907	1,791	7,287	7,439	5,644
General and administrative	10,634	12,536	9,534	9,396	10,447	11,640	8,994	8,554	42,100	39,635	36,934
Total costs and expenses	152,819	144,409	132,470	138,141	136,437	129,100	120,707	123,996	567,839	510,240	455,059
Operating income	63,135	48,984	42,256	55,986	53,536	45,956	37,887	43,436	210,361	180,815	143,276
Interest expense	(414)	(313)	(146)	(375)	(346)	(576)	(356)	(523)	(1,248)	(1,801)	(2,244)
Interest income and other	(691)	201	127	257	307	43	197	137	(106)	684	3,863
Income before income taxes	62,030	48,872	42,237	55,868	53,497	45,423	37,728	43,050	209,007	179,698	144,895
Income tax expense	23,916	15,530	16,461	21,689	20,404	16,407	14,659	16,762	77,596	68,232	56,184
Net income	$ 38,114	$ 33,342	$ 25,776	$ 34,179	$ 33,093	$ 29,016	$ 23,069	$ 26,288	$ 131,411	$ 111,466	$ 88,711
Earnings per share:
Basic income per share	$ 0.83	$ 0.72	$ 0.56	$ 0.75	$ 0.72	$ 0.64	$ 0.51	$ 0.58	$ 2.86	$ 2.45	$ 1.98
Diluted income per share	$ 0.81	$ 0.70	$ 0.55	$ 0.72	$ 0.70	$ 0.62	$ 0.49	$ 0.56	$ 2.78	$ 2.37	$ 1.92
Basic weighted average shares outstanding	46,035	46,063	46,012	45,789	45,652	45,651	45,598	45,205	45,975	45,538	44,731
Diluted weighted average shares outstanding	47,337	47,320	47,263	47,201	47,097	47,051	46,990	46,841	47,281	47,006	46,131

Admissions advisory and related expenses.

No definition available.

Name:	lope_AdmissionsAdvisoryAndRelatedExpenses
Namespace Prefix:	lope_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Costs directly attributable to educational services, including salaries and benefits for full-time faculty, administrators and academic advisors, and costs associated with adjunct faculty. Also includes costs for educational supplies such as books, costs associated with academic records and graduation, costs associated with collections from our students such as bad debt expense, and other university services such as evaluating transcripts.

+ References

No definition available.