XML 144 R129.htm IDEA: XBRL DOCUMENT v3.20.1
CONTINGENCIES - Performance Bonds (Details) - USD ($)
Dec. 31, 2019
Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]    
Malpractice loss contingency, letters of credit and surety bonds $ 13,660,000 $ 16,003,000