XML 153 R124.htm IDEA: XBRL DOCUMENT v3.21.1
INCOME TAX - Movement of the valuation allowance (Details) - CNY (¥)
¥ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Movement of the valuation allowance      
Balance at the beginning of the year ¥ 205,976 ¥ 155,852 ¥ 152,241
Increase during the year 122,845 50,124 3,611
Balance at the end of the year ¥ 328,821 ¥ 205,976 ¥ 155,852