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

Summary of Significant Accounting Policies - Narrative (Details)

v3.19.3.a.u2
Summary of Significant Accounting Policies - Narrative (Details) - USD ($)
$ in Thousands
1 Months Ended 2 Months Ended 3 Months Ended 8 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2019
Aug. 31, 2019
Sep. 30, 2018
Aug. 31, 2019
Sep. 30, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]                
Trade receivables, allowance for doubtful accounts $ 912         $ 3,759 $ 4,162  
Inventory           4,868 3,495  
Amortization of intangible assets $ 17,302 $ 32,508 $ 52,671 $ 130,791 $ 160,973 $ 211,639 236,788 $ 246,753
Employee Stock Option                
Finite-Lived Intangible Assets [Line Items]                
Dividend rate           0.00%    
Subscriber Accounts                
Finite-Lived Intangible Assets [Line Items]                
Acquired finite-lived intangible assets, useful life           15 years    
Amortization rate using declining balance method           220.00%    
Amortization of intangible assets           $ 204,130 226,697 236,673
Dealer Networks and Other Intangible Assets                
Finite-Lived Intangible Assets [Line Items]                
Amortization of intangible assets           $ 6,994 $ 9,830 $ 9,830
Finite-lived intangible asset, useful life           5 years    
LiveWatch Trademark                
Finite-Lived Intangible Assets [Line Items]                
Finite-lived intangible asset, useful life           10 years    
Security Networks LLC and Certain Affiliated Entities | Subscriber Accounts                
Finite-Lived Intangible Assets [Line Items]                
Acquired finite-lived intangible assets, useful life           14 years    
Amortization rate using declining balance method           235.00%