Subordinated Debentures - Activities for our subordinated debentures (Details) - Subordinated Debentures - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Average balance outstanding	$ 107,732	$ 81,466
Maximum amount outstanding at any month-end during the year	110,313	105,123
Balance outstanding at end of year	$ 110,313	$ 105,123
Weighted average interest rate during the year	6.23%	5.80%