Fair Value of Financial Instruments - Narrative (Details) - Level 2 - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Market Approach Valuation Technique | Junior subordinated notes
Financial Instruments Not Measured at Fair Value
Market interest rate (as a percent)	6.63%	7.79%
Market Approach Valuation Technique | Mortgages | Minimum
Financial Instruments Not Measured at Fair Value
Market interest rate (as a percent)	2.87%	3.94%
Market Approach Valuation Technique | Mortgages | Maximum
Financial Instruments Not Measured at Fair Value
Market interest rate (as a percent)	4.65%	5.61%
Carrying and Fair Value | Junior subordinated notes
Financial Instruments Not Measured at Fair Value
Estimated fair value (lower) higher than carrying value	$ 9,520	$ 11,974
Carrying and Fair Value | Mortgages
Financial Instruments Not Measured at Fair Value
Estimated fair value (lower) higher than carrying value	$ 29,153	$ 19,334