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

Fair Value Measurements - Schedule of Fair Value Measured On Recurring Basis (Details)

v3.19.3.a.u2
Fair Value Measurements - Schedule of Fair Value Measured On Recurring Basis (Details) - Recurring - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Interest rate swap agreements - assets $ 0 [1] $ 10,552 [1] $ 7,058
Interest rate swap agreements - liabilities 0 [1] (6,039) [1] (13,817)
Total 0 4,513 (6,759)
Level 1      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Interest rate swap agreements - assets 0 [1] 0 [1] 0
Interest rate swap agreements - liabilities 0 [1] 0 [1] 0
Total 0 0 0
Level 2      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Interest rate swap agreements - assets 0 [1] 10,552 [1] 7,058
Interest rate swap agreements - liabilities 0 [1] (6,039) [1] (13,817)
Total 0 4,513 (6,759)
Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Interest rate swap agreements - assets 0 [1] 0 [1] 0
Interest rate swap agreements - liabilities 0 [1] 0 [1] 0
Total $ 0 $ 0 $ 0
[1] Swap asset values are included in non-current Other assets and Swap liability values are included in non-current Derivative financial instruments on the condensed consolidated balance sheets.