Regulation (Details)		4 Months Ended	9 Months Ended	12 Months Ended
	Sep. 22, 2017 item	May 31, 2014 item	Sep. 30, 2018 USD ($) item	Dec. 31, 2016 state	Dec. 31, 2014 state item
Regulation [Line Items]
Number of debt-to-earnings measures			2
Failed programs			0
Number of ineligible years			3 years
Number of subcommittees			3
Number of department public hearings convened			3
Number of consecutive years program has to fail both metrics to become ineligible			2 years
Number of consecutive years program has to fail one metric to become ineligible			4 years
Number of metrics that can't be failed for consecutive years			1
Number of guidance documents	2
Number of states needed for state authorization reciprocity agreement | state				2
Number of sessions		4
Minimum
Regulation [Line Items]
Average of median annual earning percentage			8.00%
Average of median discretionary percentage			20.00%
Licensed jurisdictions			1
Maximum
Regulation [Line Items]
Average of median annual earning percentage			12.00%
Average of median discretionary percentage			30.00%
Strayer University
Regulation [Line Items]
Number of years an adverse action must be disclosed			5 years
Number of conducted compliance reviews					2
Number of reviews in which no further action was required					3
Number of states in which compliance reviews were conducted | state					3
Strayer University | Maximum
Regulation [Line Items]
Amount due to department of education | $			$ 500
Capella | Strayer University
Regulation [Line Items]
Number of current associate degree programs in the Zone			1
Strayer
Regulation [Line Items]
Number of current associate degree programs in the Zone			2
Number of on-site reviews conducted					4