XML 52 R42.htm IDEA: XBRL DOCUMENT v3.21.2
SHORT-TERM INVESTMENTS - Interest income (Details) - CNY (¥)
¥ in Thousands
6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
SHORT-TERM INVESTMENTS    
Interest income recognized on held-to-maturity investments ¥ 672 ¥ 175