Securities (Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale debt securities maturities wIthin 1 year amortized cost	$ 69,070
Available for sale debt securities maturities 1-5 years amortized cost	328,420
Available for sale debt securities maturities 5-10 years amortized cost	337,589
Available for sale debt securities maturities after 10 years amortized cost	214,641
Available for sale securities amortized cost	949,720
Available for sale debt securities maturities within 1 year fair value	67,584
Available for sale debt securities maturities 1-5 years fair value	321,760
Available for sale debt securities maturities 5-10 years fair value	329,330
Available for sale debt securities maturities after 10 years fair value	209,136
Available for sale debt securities fair value	927,810
Held to maturity debt securities maturities within 1 year amortized cost	1,329
Held to maturity debt securities maturities 1-5 years amortized cost	4,396
Held to maturity debt securities maturities 5-10 years amortized cost	3,580
Held to maturity debt securities maturities after 10 years amortized cost	1,110
Held to maturity securities amortized cost	10,415	$ 12,541
Held to maturity debt securities maturities within 1 year fair value	1,317
Held to maturity debt securities maturities 1-5 years fair value	4,354
Held to maturity debt securities maturities 5-10 years fair value	3,546
Held to maturity debt securities maturities after 10 years fair value	1,099
Held to maturity securities fair value	10,316	12,721
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Held to maturity securities amortized cost	10,415	12,541
Held to maturity securities fair value	$ 10,316	$ 12,721