Business Acquisition - Summary of Fair Values of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 02, 2020	Dec. 31, 2019	Dec. 31, 2018
Intangible assets subject to amortization
Goodwill	$ 118,312		$ 87,356	$ 87,356
Trident [Member]
Assets:
Student receivables, net		$ 6,212
Other current assets		912
Property and equipment		3,932
Intangible assets subject to amortization
Goodwill		30,956
Deferred tax asset		454
Other non-current assets		270
Total assets acquired		53,136
Liabilities:
Accounts payable and other accrued liabilities		2,622
Deferred revenue		4,749
Loan discharge reserve		1,900
Other long-term liabilities		46
Total liabilities assumed		9,317
Net assets acquired		43,819
Trident [Member] | Trade Name [Member]
Intangible assets subject to amortization
Intangible assets subject to amortization		1,000
Trident [Member] | Student Relationships [Member]
Intangible assets subject to amortization
Intangible assets subject to amortization		8,000
Trident [Member] | Course Curriculum [Member]
Intangible assets subject to amortization
Intangible assets subject to amortization		$ 1,400