Loans and Allowance for Loan Losses (Changes in Carrying Amount of Purchased Credit Impaired Loans and Related Accretable Yield) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Loans and Allowance for Loan Losses [Abstract]
Carrying Amount of Loans, Balance at beginning of period	$ 147,537
Carrying Amount of Loans, Balance at beginning of period	153,403	$ 190,915
Carrying Amount of Loans, Additions		15,000
Carrying Amount of Loans, Payments received, net	(39,556)	(69,591)
Carrying Amount of Loans, Accretion	15,749	17,079
Carrying Amount of Loans, Balance at end of period	129,596	153,403
Accretable Yield, Balance at beginning of period	62,517	113,686
Accretable Yield, Payments received, net	(5,779)	(7,412)
Accretable Yield, Accretion	(15,749)	(17,079)
Accretable Yield, Increase (decrease) in expected cash flows based on actual cash flow and changes in cash flow assumptions	(3,695)	(30,379)
Accretable Yield, Net transfers from nonaccretable difference to accretable yield		3,701
Accretable Yield, Balance at end of period	$ 37,294	$ 62,517