Loans Receivable (Schedule Of Carrying Amount Of Acquired Covered Loans) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Loans Receivable [Line Items]
Acquired Impaired Loans	$ 62,196	$ 89,372
Acquired Performing Loans	1,127,951	1,245,077
Total Covered Loans	1,190,147	1,334,449
Residential Mortgage Loans [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans	30,089	31,809
Acquired Performing Loans	153,479	184,465
Total Covered Loans	183,568	216,274
Residential Mortgage Loans [Member] | Residential 1-4 Family [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans	30,089	31,809
Acquired Performing Loans	153,479	184,465
Total Covered Loans	183,568	216,274
Commercial Loans [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans	7,272	27,180
Acquired Performing Loans	771,763	849,666
Total Covered Loans	779,035	876,846
Commercial Loans [Member] | Real Estate [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans	4,789	23,127
Acquired Performing Loans	648,565	704,841
Total Covered Loans	653,354	727,968
Commercial Loans [Member] | Business [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans	2,483	4,053
Acquired Performing Loans	123,198	144,825
Total Covered Loans	125,681	148,878
Consumer And Other Loans [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans	24,835	30,383
Acquired Performing Loans	202,709	210,946
Total Covered Loans	227,544	241,329
Consumer And Other Loans [Member] | Home Equity [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans	24,835	30,267
Acquired Performing Loans	193,001	204,707
Total Covered Loans	217,836	234,974
Consumer And Other Loans [Member] | Consumer - Other [Member]
Loans Receivable [Line Items]
Acquired Impaired Loans		116
Acquired Performing Loans	9,708	6,239
Total Covered Loans	$ 9,708	$ 6,355