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Acquisitions - 2019 Acquisition Summary of Fair Value of the Consideration (Details) - USD ($) $ in Thousands			12 Months Ended
	Oct. 01, 2019	Jul. 02, 2018	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill			$ 149,524	$ 285,214	$ 214,513
Thinkful, Inc
Business Acquisition [Line Items]
Cash	$ 51
Accounts receivable	547
Other acquired assets	1,710
Acquired intangible assets	16,360
Total identifiable assets acquired	18,668
Deferred revenue	(2,455)
Liabilities assumed	(1,906)
Net identifiable assets acquired	14,307
Goodwill	64,893
Total fair value of purchase consideration	79,200
WriteLab, Inc. And StudyBlue, Inc.
Business Acquisition [Line Items]
Cash			234
Accounts receivable			482
Acquired intangible assets			11,550
Total identifiable assets acquired			12,417
Liabilities assumed			(2,206)
Net identifiable assets acquired			10,211
Goodwill			24,673
Total fair value of purchase consideration			$ 34,884
Weighted average amortization period			72 months
StudyBlue, Inc.
Business Acquisition [Line Items]
Cash		$ 152
Accounts receivable		288
Acquired intangible assets		7,100
Total identifiable assets acquired		7,691
Liabilities assumed		(1,309)
Net identifiable assets acquired		6,382
Goodwill		13,996
Total fair value of purchase consideration		$ 20,378
Weighted average amortization period		57 months
Trade name \| Thinkful, Inc
Business Acquisition [Line Items]
Acquired intangible assets	$ 4,430
Weighted average amortization period	48 months
Trade name \| WriteLab, Inc. And StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets			$ 140
Weighted average amortization period			12 months
Trade name \| StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets		$ 140
Weighted average amortization period		12 months
Domain names \| Thinkful, Inc
Business Acquisition [Line Items]
Acquired intangible assets	$ 330
Weighted average amortization period	48 months
Domain names \| WriteLab, Inc. And StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets			$ 180
Weighted average amortization period			12 months
Domain names \| StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets		$ 180
Weighted average amortization period		12 months
Content library \| Thinkful, Inc
Business Acquisition [Line Items]
Acquired intangible assets	$ 6,940
Weighted average amortization period	60 months
Content library \| WriteLab, Inc. And StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets			$ 5,220
Weighted average amortization period			60 months
Content library \| StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets		$ 5,220
Weighted average amortization period		60 months
Developed technology \| Thinkful, Inc
Business Acquisition [Line Items]
Acquired intangible assets	$ 4,660
Weighted average amortization period	36 months
Developed technology \| WriteLab, Inc. And StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets			$ 5,790
Weighted average amortization period			88 months
Developed technology \| StudyBlue, Inc.
Business Acquisition [Line Items]
Acquired intangible assets		$ 1,340
Weighted average amortization period		60 months
Acquired intangible assets \| Thinkful, Inc
Business Acquisition [Line Items]
Acquired intangible assets	$ 16,360
Weighted average amortization period	50 months