v3.19.3.a.u2
Significant Accounting Policies (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Jan. 01, 2019
Jan. 01, 2017
Property and Equipment, Net                    
Impairment charge $ 0 $ 70,379 $ 0 $ 0   $ 70,379 $ 0 $ 0    
Equity securities 10,000         10,000        
Investments         $ 25,000   25,000      
Non-Cash Long-Lived Asset Additions                    
Capital asset additions during the period           81,400 87,400      
Non-cash capital expenditure           (3,100) (5,300)      
Additional cash classified as cash flows from financing activities           (2,200) 4,900      
Marketing and Sales Costs                    
Accrued marketing costs 22,100       10,300 22,100 $ 10,300      
Capitalized software implementation costs         $ 400 3,100        
Amortization of capitalized software implementation costs           (300)        
Right-of-use assets 43,401         43,401        
Lease liability, current 7,320         7,320        
Lease liability 74,294         $ 74,294        
Minimum                    
Amortizable Intangible Assets                    
Estimated useful life of intangible assets           3 years        
Maximum                    
Amortizable Intangible Assets                    
Estimated useful life of intangible assets           10 years        
Computer hardware | Minimum                    
Property and Equipment, Net                    
Useful lives           3 years        
Computer hardware | Maximum                    
Property and Equipment, Net                    
Useful lives           5 years        
Furniture and office equipment | Minimum                    
Property and Equipment, Net                    
Useful lives           5 years        
Furniture and office equipment | Maximum                    
Property and Equipment, Net                    
Useful lives           7 years        
Leasehold improvements | Minimum                    
Property and Equipment, Net                    
Useful lives           4 years        
Leasehold improvements | Maximum                    
Property and Equipment, Net                    
Useful lives           11 years        
Internally-developed software | Minimum                    
Amortizable Intangible Assets                    
Estimated useful life of intangible assets           3 years        
Useful life of capitalized content development costs           4 years        
Internally-developed software | Maximum                    
Amortizable Intangible Assets                    
Estimated useful life of intangible assets           5 years        
Useful life of capitalized content development costs           5 years        
Graduate Program Segment                    
Property and Equipment, Net                    
Impairment charge           $ 0        
Revenue, performance obligation, description of timing           The Company’s contracts with university clients in this segment typically have terms of 10 to 15 years and have a single performance obligation, as the promises to provide a platform of tightly integrated technology and services that university clients need to attract, enroll, educate and support students are not distinct within the context of the contracts.        
Alternative Credential Segment                    
Property and Equipment, Net                    
Impairment charge           $ 70,379        
Revenue, performance obligation, description of timing           The Company’s short courses run between six and 16 weeks, while boot camps run between 12 and 24 weeks.        
ASU 2016-09 | Additional Paid-In Capital                    
Marketing and Sales Costs                    
Cumulative effect of new accounting policy                   $ 100
ASU 2016-02                    
Marketing and Sales Costs                    
Right-of-use assets                 $ 34,000  
Lease liability, current                 $ 5,000  
Lease liability $ 58,000         $ 58,000