Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of cash flows specific transaction amounts [Abstract]
Interest expense paid on deposits and borrowings	$ 20,501	$ 13,902
Noncash transfers from loans to other real estate	785	$ 2,010
Securities purchased not settled	1,095
Finance right-of-use assets resulting from lease liabilities	11,230
Operating right-of-use assets resulting from lease liabilities	$ 33,861