Securities (Amortized Cost and Fair Value of Securities, by Contractual Maturities) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Available for Sale, Due in one year or less, Amortized Cost	$ 40,243
Available for Sale, Due in one year or less, Fair Value	40,720
Available for Sale, Due from one to five years, Amortized Cost	289,370
Available for Sale, Due from one to five years, Fair Value	290,091
Available for Sale, Due from five to ten years, Amortized Cost	12,671
Available for Sale, Due from five to ten years, Fair Value	12,996
Available for Sale, Due after ten years, Amortized Cost	59,819
Available for Sale, Due after ten years, Fair Value	46,985
Available for Sale, with contractual maturities, Amortized Cost	402,103
Available for Sale, with contractual maturities, Fair Value	390,792
Total securities available for sale, Amortized Cost	822,860	744,292
Available-for-sale Securities, Fair Value	820,847	738,125
Held to Maturity, Due in one year or less, Amortized Cost	6,339
Held to Maturity, Due in one year or less, Fair Value	6,438
Held to Maturity, Due from one to five years, Amortized Cost	16,728
Held to Maturity, Due from one to five years, Fair Value	17,443
Held to Maturity, Due from five to ten years, Amortized Cost	36,047
Held to Maturity, Due from five to ten years, Fair Value	36,875
Held to Maturity, Due after ten years, Amortized Cost	102,213
Held to Maturity, Due after ten years, Fair Value	103,385
Held to Maturity, Amortized Cost, total	1,010,672	940,481
Held to Maturity, Fair Value, total	1,038,434	959,414
Held to Maturity, with contractual maturities, Amortized Cost	161,327
Held to Maturity, with contractual maturities, Fair Value	164,141
Agency Mortgage Backed Securities [Member]
Total securities available for sale, Amortized Cost	234,465	205,443
Available-for-sale Securities, Fair Value	241,148	211,507
Held to Maturity, Amortized Cost, total	758,325
Held to Maturity, Fair Value, total	783,493
Agency Collateralized Mortgage Obligations [Member]
Total securities available for sale, Amortized Cost	184,665	146,977
Available-for-sale Securities, Fair Value	186,985	147,866
Held to Maturity, Amortized Cost, total	62,673
Held to Maturity, Fair Value, total	63,118
Non-Agency Collateralized Mortgage Obligations [Member]
Total securities available for sale, Amortized Cost	34	37
Available-for-sale Securities, Fair Value	35	38
Held to Maturity, Amortized Cost, total	28,347
Held to Maturity, Fair Value, total	27,682
Equity Securities [Member]
Total securities available for sale, Amortized Cost	1,593	1,867
Available-for-sale Securities, Fair Value	$ 1,887	$ 2,189

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For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading. Such securities are reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain or loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis.

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This item represents the total of all debt securities grouped by maturity dates, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are classified as held-to-maturity.

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This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and which are categorized as held-to-maturity.

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This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.

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