Short-Term Borrowings and Long-Term FHLB Advances - Information Concerning Short-term Borrowings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Long-term Federal Home Loan Bank Advances [Abstract]
Balance at period-end	$ 124,214	$ 173,704	$ 252,367
Maximum amount outstanding at any month end	184,257	173,704
Average balance outstanding during the period	$ 179,754	$ 172,532
Weighted-average interest rate:
As of the period-end (as a percent)	2.47%	1.76%
Paid during the period (as a percent)	2.43%	1.48%