Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Statement Of Cash Flows [Abstract]
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 66,015	$ 46,276
INVESTING ACTIVITIES:
Net increase in loans	(115,220)	(54,935)
Securities available-for-sale:
Proceeds from sales	9,265	42,810
Proceeds from maturities, prepayments and calls	147,472	276,664
Purchases of securities	(126,546)	(327,595)
Securities held-to-maturity:
Proceeds from maturities, prepayments and calls	57,719	58,668
Purchases of securities	(65,576)	(40,239)
Purchases of premises and equipment - net	(3,989)	(1,497)
Sale of portfolio loans - net		2,852
Net cash used in investing activities	(96,875)	(43,272)
FINANCING ACTIVITIES:
Decrease in deposits	(6,176)	(90)
Repayment of Federal Home Loan Bank borrowings	(50,415)	(26,191)
Increase (decrease) in other short-term borrowings	1,813	(5,375)
Increase in federal funds	56,000
Repayment of junior subordinated debt	(7,732)
Dividends paid to common shareholders	(10,811)	(8,788)
Treasury shares purchased - net	(274)	(70)
Issuance of common stock	920
Net cash used in financing activities	(16,675)	(40,514)
Net decrease in cash and cash equivalents	(47,535)	(37,510)
Cash and cash equivalents at beginning of the period	125,605	140,325
Cash and cash equivalents at end of the period	78,070	102,815
SUPPLEMENTAL DISCLOSURES:
Interest paid on deposits and other borrowings	17,549	23,421
Income taxes paid	11,425	6,445
Transfers of loans to other real estate owned	1,084	2,424
Transfers of loans to held for sale		$ 5,075