Fair Value Measurements (Carrying Amounts and Estimated Fair Values) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investment securities:
Available-for-sale	$ 684,570	$ 586,809
Held-to-maturity Securities, Fair Value	268,271	229,922
Carrying Amount [Member]
Investment securities:
Available-for-sale	0	4,755
Nonmarketable equity securities	25,572	25,572
Carrying Amount [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	310,788	656,135
Carrying Amount [Member] | Level 2 [Member]
Investment securities:
Available-for-sale	684,570	582,054
Held-to-maturity Securities, Fair Value	263,405	229,977
Loans held-for-sale	5,219	17,665
Interest receivable	15,748	14,933
Liabilities:
Deposits without defined maturities	3,790,454	3,448,886
Interest Payable	868	1,501
Short-term borrowings	327,428	310,463
FHLB advances	0	34,289
Carrying Amount [Member] | Level 3 [Member]
Investment securities:
Held-to-maturity Securities, Fair Value	10,500	0
Net loans	4,568,549	4,083,244
Liabilities:
Time deposits	1,331,931	1,472,557
Fair Value [Member]
Investment securities:
Available-for-sale	0	4,755
Nonmarketable equity securities	25,572	25,572
Fair Value [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	310,788	656,135
Fair Value [Member] | Level 2 [Member]
Investment securities:
Available-for-sale	684,570	582,054
Held-to-maturity Securities, Fair Value	262,021	229,922
Loans held-for-sale	5,219	17,665
Interest receivable	15,748	14,933
Liabilities:
Deposits without defined maturities	3,790,454	3,448,886
Interest Payable	868	1,501
Short-term borrowings	327,428	310,463
FHLB advances	0	34,835
Fair Value [Member] | Level 3 [Member]
Investment securities:
Held-to-maturity Securities, Fair Value	6,250	0
Net loans	4,575,532	4,093,880
Liabilities:
Time deposits	$ 1,340,746	$ 1,489,072