Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands			3 Months Ended
	Jan. 01, 2020 USD ($)	Jul. 01, 2018 USD ($)	Mar. 31, 2020 USD ($) item segment	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Funding to GCU for capital expenditures				$ 29,905
Other assets			$ 1,754		$ 1,706
Number of operating segments | segment			1
Number of reporting units | segment			1
Unbilled revenue			$ 400
Amounts written off			0
Allowance for doubtful accounts			0
Lease liabilities			$ 35,922
Number of university partners | item			24
Accounts receivable credit losses			$ 0
Allowance for credit losses	$ 5,000		5,000
Retained earnings			1,408,897		$ 1,341,344
Income tax expense			$ 22,791	$ 11,456
Computer Software
Summary Of Significant Accounting Policies [Line Items]
Estimated average useful life			3 years
Capitalized Content Development
Summary Of Significant Accounting Policies [Line Items]
Estimated average useful life			4 years
Other assets			$ 1,044
Interest Rate Corridor | 30 Day LIBOR equal to 1.5% through 3.0%
Summary Of Significant Accounting Policies [Line Items]
Interest rate spread on 30 Day LIBOR			1.50%
Interest Rate Corridor | 30 Day LIBOR exceeds 3.0%
Summary Of Significant Accounting Policies [Line Items]
Interest rate spread on 30 Day LIBOR			1.50%
Cash Flow Hedging
Summary Of Significant Accounting Policies [Line Items]
Effective portion of losses on derivatives included as a component of other comprehensive income, net of taxes			$ 142
Other Assets
Summary Of Significant Accounting Policies [Line Items]
Fair values of interest rate corridor instrument			$ 423
Minimum
Summary Of Significant Accounting Policies [Line Items]
Initial contract terms			7 years
Minimum | Interest Rate Corridor | 30 Day LIBOR equal to 1.5% through 3.0%
Summary Of Significant Accounting Policies [Line Items]
30 Day LIBOR index rate			1.50%
Minimum | Interest Rate Corridor | 30 Day LIBOR exceeds 3.0%
Summary Of Significant Accounting Policies [Line Items]
30 Day LIBOR index rate			3.00%
Maximum
Summary Of Significant Accounting Policies [Line Items]
Initial contract terms			15 years
Maximum | Interest Rate Corridor | 30-day LIBOR
Summary Of Significant Accounting Policies [Line Items]
30 Day LIBOR index rate			1.50%
Maximum | Interest Rate Corridor | 30 Day LIBOR equal to 1.5% through 3.0%
Summary Of Significant Accounting Policies [Line Items]
30 Day LIBOR index rate			3.00%
Grand Canyon University
Summary Of Significant Accounting Policies [Line Items]
Purchase price of assets		$ 870,097
Interest rate on Secured Note		6.00%
Term of additional lending to GCU for approved capital expenditures		3 years
Funding to GCU for capital expenditures			$ 99,815
Master Services Agreement | Grand Canyon University
Summary Of Significant Accounting Policies [Line Items]
Percentage of tuition and fee revenue used for closing of purchase agreement		60.00%
Restatement Adjustment | ASU 2016-13
Summary Of Significant Accounting Policies [Line Items]
Allowance for credit losses	5,000
Retained earnings	(3,832)
Income tax expense	$ 1,168