Loans Receivable, Net (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Dec. 31, 2011
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	$ 74,256	$ 74,256	$ 77,717
Loans with a specific valuation allowance, Unpaid principal balance	84,807	84,807	85,514
Loans with a specific valuation allowance, Average balance	78,067	80,131	66,871
Loans without a specific valuation allowance, Recorded balance	152,184	152,184	180,942
Loans without a specific valuation allowance, Unpaid principal balance	164,411	164,411	208,828
Loans without a specific valuation allowance, Average balance	154,105	168,387	168,983
Recorded balance	226,440	226,440	258,659
Unpaid principal balance	249,218	249,218	294,342
Specific valuation allowance	18,562	18,562	18,828
Average balance	232,172	248,518	235,854
Residential Real Estate [Member]
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	11,663	11,663	11,111
Loans with a specific valuation allowance, Unpaid principal balance	11,787	11,787	11,177
Loans with a specific valuation allowance, Average balance	15,010	14,163	10,330
Loans without a specific valuation allowance, Recorded balance	18,282	18,282	13,342
Loans without a specific valuation allowance, Unpaid principal balance	19,041	19,041	14,741
Loans without a specific valuation allowance, Average balance	16,771	15,411	14,730
Recorded balance	29,945	29,945	24,453
Unpaid principal balance	30,828	30,828	25,918
Specific valuation allowance	3,252	3,252	2,659
Average balance	31,781	29,574	25,060
Commercial Real Estate [Member]
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	34,943	34,943	39,971
Loans with a specific valuation allowance, Unpaid principal balance	44,929	44,929	47,569
Loans with a specific valuation allowance, Average balance	35,513	37,807	38,805
Loans without a specific valuation allowance, Recorded balance	106,774	106,774	122,988
Loans without a specific valuation allowance, Unpaid principal balance	116,157	116,157	139,962
Loans without a specific valuation allowance, Average balance	107,599	115,520	123,231
Recorded balance	141,717	141,717	162,959
Unpaid principal balance	161,086	161,086	187,531
Specific valuation allowance	8,410	8,410	9,756
Average balance	143,112	153,327	162,036
Other Commercial [Member]
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	22,354	22,354	22,087
Loans with a specific valuation allowance, Unpaid principal balance	22,743	22,743	22,196
Loans with a specific valuation allowance, Average balance	21,981	23,030	13,395
Loans without a specific valuation allowance, Recorded balance	13,318	13,318	27,875
Loans without a specific valuation allowance, Unpaid principal balance	14,863	14,863	35,174
Loans without a specific valuation allowance, Average balance	15,207	21,569	19,963
Recorded balance	35,672	35,672	49,962
Unpaid principal balance	37,606	37,606	57,370
Specific valuation allowance	4,436	4,436	4,233
Average balance	37,188	44,599	33,358
Home Equity [Member]
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	804	804	1,219
Loans with a specific valuation allowance, Unpaid principal balance	852	852	1,238
Loans with a specific valuation allowance, Average balance	1,326	1,398	1,284
Loans without a specific valuation allowance, Recorded balance	11,250	11,250	13,531
Loans without a specific valuation allowance, Unpaid principal balance	11,753	11,753	15,097
Loans without a specific valuation allowance, Average balance	11,452	12,562	8,975
Recorded balance	12,054	12,054	14,750
Unpaid principal balance	12,605	12,605	16,335
Specific valuation allowance	257	257	584
Average balance	12,778	13,960	10,259
Other Consumer [Member]
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	4,492	4,492	3,329
Loans with a specific valuation allowance, Unpaid principal balance	4,496	4,496	3,334
Loans with a specific valuation allowance, Average balance	4,237	3,733	3,057
Loans without a specific valuation allowance, Recorded balance	2,560	2,560	3,206
Loans without a specific valuation allowance, Unpaid principal balance	2,597	2,597	3,854
Loans without a specific valuation allowance, Average balance	3,076	3,325	2,084
Recorded balance	7,052	7,052	6,535
Unpaid principal balance	7,093	7,093	7,188
Specific valuation allowance	2,207	2,207	1,596
Average balance	$ 7,313	$ 7,058	$ 5,141