Loans (Summary of Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Summary of loans under portfolio
Commercial loan	$ 4,308,209	$ 4,250,117	$ 3,081,931
Consumer loan	3,058,676	3,021,030	2,620,943
Total loans	7,366,885	7,271,147	5,702,874
Commercial [Member]
Summary of loans under portfolio
Commercial loan	1,922,259	1,905,879	1,356,169
Real estate commercial [Member]
Summary of loans under portfolio
Commercial loan	2,143,051	2,112,162	1,616,923
Real estate construction [Member]
Summary of loans under portfolio
Commercial loan	242,899	232,076	108,839
Real estate residential [Member]
Summary of loans under portfolio
Consumer loan	1,461,120	1,429,636	1,117,445
Consumer installment [Member]
Summary of loans under portfolio
Consumer loan	897,078	877,457	844,066
Home equity [Member]
Summary of loans under portfolio
Consumer loan	$ 700,478	$ 713,937	$ 659,432