Acquisition Activity (Schedule Of Preliminary Purchase Price Allocation) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Trading securities	$ 2,816
Investment securities - available for sale	2,071,276	1,960,222
Investment securities - held to maturity	484,590	638,210
Federal Home Loan Bank stock, at cost	30,835	31,937
Deposits	(6,611,563)	(5,462,925)
Short-term borrowings	(424,849)	(298,232)
Purchase price	90,070
Monroe Bancorp [Member]
Cash and cash equivalents	83,604
Trading securities	3,877
Investment securities - available for sale	140,422
Investment securities - held to maturity	6,972
Federal Home Loan Bank stock, at cost	2,323
Loans held for sale	6,328
Loans	447,038
Premises and equipment	19,738
Accrued interest receivable	1,804
Company-owned life insurance	17,206
Other assets	41,538
Deposits	(653,813)
Short-term borrowings	(62,529)
Other borrowings	(37,352)
Accrued expenses and other liabilities	(6,000)
Net tangible assets acquired	11,156
Definite-lived intangible assets acquired	10,485
Goodwill	68,429
Purchase price	$ 90,070