Significant Accounting Policies (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) Banks ATM branches	Dec. 31, 2016 USD ($)
Basis Of Presentation [Line Items]
Number of bank divisions | Banks	28
Number of branches | branches	248
Number of ATMs | ATM	327
Share-based compensation, excess tax benefit	$ 4,100
Cash and Cash Equivalents [Member]
Basis Of Presentation [Line Items]
Total deposits		$ 533
Cash and cash equivalents	122,600	130,000
Interest earning deposits with banks	5,500	5,600
Federal funds sold	$ 49,100	$ 56,100