General form of registration statement for all companies including face-amount certificate companies

Goodwill - Schedule of Goodwill (Details)

v3.19.3.a.u2
Goodwill - Schedule of Goodwill (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 8 Months Ended 9 Months Ended 12 Months Ended
Jun. 30, 2018
Sep. 30, 2019
Dec. 31, 2018
Jun. 30, 2018
Aug. 31, 2019
Sep. 30, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Goodwill [Roll Forward]                  
Goodwill, Beginning Balance         $ 0 $ 563,549 $ 563,549 $ 563,549  
Period activity               0  
Goodwill impairment   $ 0     0 (214,400) (563,549) 0 $ 0
Reporting unit reallocation             0    
Goodwill, Ending Balance   $ 81,943 $ 0       0 563,549 563,549
MONI                  
Goodwill [Roll Forward]                  
Goodwill, Beginning Balance         0 527,502 527,502 527,502  
Period activity               0  
Goodwill impairment       $ (214,400)     (214,400)    
Reporting unit reallocation $ (313,102)           (313,102)    
Goodwill, Ending Balance     0       0 527,502 527,502
LiveWatch                  
Goodwill [Roll Forward]                  
Goodwill, Beginning Balance         0 36,047 36,047 36,047  
Period activity               0  
Goodwill impairment             0    
Reporting unit reallocation $ (36,047)           (36,047)    
Goodwill, Ending Balance     0       0 36,047 36,047
Brinks Home Security                  
Goodwill [Roll Forward]                  
Goodwill, Beginning Balance         $ 0 $ 0 0 0  
Period activity               0  
Goodwill impairment     (349,149)       (349,149)    
Reporting unit reallocation             349,149    
Goodwill, Ending Balance     $ 0       $ 0 $ 0 $ 0