Short-Term Borrowings (Short-Term Federal Home Loan Bank Borrowings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Amount outstanding at end of year	$ 394,480	$ 333,909
Federal Home Loan Bank Advances [Member]
Short-term Debt [Line Items]
Average daily balance during the year	357,848	295,479
Maximum month-end balance during the year	410,050	342,000
Amount outstanding at end of year	$ 372,700	$ 313,000