XML 73 R36.htm IDEA: XBRL DOCUMENT v3.20.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)
$ in Thousands
3 Months Ended
Jan. 02, 2020
USD ($)
Mar. 31, 2020
USD ($)
Segment
Mar. 31, 2019
USD ($)
Revenue Recognition Arrangements [Line Items]      
Number Of Operating Segments | Segment   3  
Stock options granted to directors, contractual term   10 years  
Other comprehensive income (loss), tax   $ 0 $ 0
Consumer Language      
Revenue Recognition Arrangements [Line Items]      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period   24 months  
Minimum      
Revenue Recognition Arrangements [Line Items]      
Contract with customer credit card settlement period   7 days  
Minimum | Consumer Language      
Revenue Recognition Arrangements [Line Items]      
Contract with customer payment terms   30 days  
Minimum | E&E Language      
Revenue Recognition Arrangements [Line Items]      
Contract with customer payment terms   30 days  
Minimum | Literacy      
Revenue Recognition Arrangements [Line Items]      
Contract with customer payment terms   30 days  
Maximum      
Revenue Recognition Arrangements [Line Items]      
Contract with customer credit card settlement period   10 days  
Maximum | Consumer Language      
Revenue Recognition Arrangements [Line Items]      
Contract with customer payment terms   45 days  
Maximum | E&E Language      
Revenue Recognition Arrangements [Line Items]      
Contract with customer payment terms   90 days  
Maximum | Literacy      
Revenue Recognition Arrangements [Line Items]      
Contract with customer payment terms   90 days  
ASU 2016-13 | Maximum      
Revenue Recognition Arrangements [Line Items]      
Decrease in bad debt reserves $ 100