Statements of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019
Statement of cash flows specific transaction amounts [Abstract]
Income taxes paid	$ 5,336	$ 4,620
Interest expense paid on deposits and borrowings	43,004	29,045
Noncash transfers from loans to other real estate	2,101	$ 7,084
Finance right-of-use assets resulting from lease liabilities	10,698
Operating right-of-use assets resulting from lease liabilities	$ 32,762		$ 33,900