Loans receivable (Details 4) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Loan delinquencies
Recorded investment in loans receivable	$ 6,064,864	$ 5,989,891
Percentage of total loans receivable	100.00%	100.00%
90 days or greater delinquent	32,913	41,326
Percentage of total loans 90 or more days delinquent	100.00%	100.00%
Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	4,575,624	4,542,379
Percentage of total loans receivable	75.50%	75.80%
90 days or greater delinquent	24,707	30,630
Percentage of total loans 90 or more days delinquent	75.10%	74.10%
New York
Loan delinquencies
Recorded investment in loans receivable	1,006,559	961,051
Percentage of total loans receivable	16.60%	16.00%
90 days or greater delinquent	3,548	3,584
Percentage of total loans 90 or more days delinquent	10.80%	8.70%
Ohio
Loan delinquencies
Recorded investment in loans receivable	71,734	71,432
Percentage of total loans receivable	1.20%	1.20%
90 days or greater delinquent	610	752
Percentage of total loans 90 or more days delinquent	1.90%	1.80%
Maryland
Loan delinquencies
Recorded investment in loans receivable	281,804	285,426
Percentage of total loans receivable	4.60%	4.80%
90 days or greater delinquent	2,349	3,213
Percentage of total loans 90 or more days delinquent	7.10%	7.80%
Other
Loan delinquencies
Recorded investment in loans receivable	129,143	129,603
Percentage of total loans receivable	2.10%	2.20%
90 days or greater delinquent	1,699	3,147
Percentage of total loans 90 or more days delinquent	5.20%	7.60%
Personal Banking
Loan delinquencies
Recorded investment in loans receivable	3,839,565	3,830,331
90 days or greater delinquent	22,759	26,752
Personal Banking | Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	3,295,746	3,285,588
90 days or greater delinquent	16,235	19,144
Personal Banking | New York
Loan delinquencies
Recorded investment in loans receivable	289,097	286,865
90 days or greater delinquent	2,306	2,228
Personal Banking | Ohio
Loan delinquencies
Recorded investment in loans receivable	30,992	30,705
90 days or greater delinquent	610	752
Personal Banking | Maryland
Loan delinquencies
Recorded investment in loans receivable	160,206	162,759
90 days or greater delinquent	2,322	2,736
Personal Banking | Other
Loan delinquencies
Recorded investment in loans receivable	63,524	64,414
90 days or greater delinquent	1,286	1,892
Personal Banking | Residential mortgage loans
Loan delinquencies
Recorded investment in loans receivable	2,543,870	2,521,456
90 days or greater delinquent	15,068	17,696
Personal Banking | Residential mortgage loans | Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	2,176,741	2,151,361
90 days or greater delinquent	10,771	12,282
Personal Banking | Residential mortgage loans | New York
Loan delinquencies
Recorded investment in loans receivable	160,609	161,445
90 days or greater delinquent	1,229	1,237
Personal Banking | Residential mortgage loans | Ohio
Loan delinquencies
Recorded investment in loans receivable	18,705	18,486
90 days or greater delinquent	602	710
Personal Banking | Residential mortgage loans | Maryland
Loan delinquencies
Recorded investment in loans receivable	132,630	134,228
90 days or greater delinquent	1,221	1,678
Personal Banking | Residential mortgage loans | Other
Loan delinquencies
Recorded investment in loans receivable	55,185	55,936
90 days or greater delinquent	1,245	1,789
Personal Banking | Home equity loans
Loan delinquencies
Recorded investment in loans receivable	1,055,739	1,066,131
90 days or greater delinquent	5,646	6,606
Personal Banking | Home equity loans | Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	897,681	909,139
90 days or greater delinquent	3,510	4,474
Personal Banking | Home equity loans | New York
Loan delinquencies
Recorded investment in loans receivable	117,853	115,459
90 days or greater delinquent	1,012	936
Personal Banking | Home equity loans | Ohio
Loan delinquencies
Recorded investment in loans receivable	8,910	9,087
90 days or greater delinquent		35
Personal Banking | Home equity loans | Maryland
Loan delinquencies
Recorded investment in loans receivable	26,217	27,203
90 days or greater delinquent	1,083	1,058
Personal Banking | Home equity loans | Other
Loan delinquencies
Recorded investment in loans receivable	5,078	5,243
90 days or greater delinquent	41	103
Personal Banking | Other consumer loans
Loan delinquencies
Recorded investment in loans receivable	239,956	242,744
90 days or greater delinquent	2,045	2,450
Personal Banking | Other consumer loans | Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	221,324	225,088
90 days or greater delinquent	1,954	2,388
Personal Banking | Other consumer loans | New York
Loan delinquencies
Recorded investment in loans receivable	10,635	9,961
90 days or greater delinquent	65	55
Personal Banking | Other consumer loans | Ohio
Loan delinquencies
Recorded investment in loans receivable	3,377	3,132
90 days or greater delinquent	8	7
Personal Banking | Other consumer loans | Maryland
Loan delinquencies
Recorded investment in loans receivable	1,359	1,328
90 days or greater delinquent	18
Personal Banking | Other consumer loans | Other
Loan delinquencies
Recorded investment in loans receivable	3,261	3,235
Business Banking
Loan delinquencies
Recorded investment in loans receivable	2,225,299	2,159,560
90 days or greater delinquent	10,154	14,574
Business Banking | Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	1,279,878	1,256,791
90 days or greater delinquent	8,472	11,486
Business Banking | New York
Loan delinquencies
Recorded investment in loans receivable	717,462	674,186
90 days or greater delinquent	1,242	1,356
Business Banking | Ohio
Loan delinquencies
Recorded investment in loans receivable	40,742	40,727
Business Banking | Maryland
Loan delinquencies
Recorded investment in loans receivable	121,598	122,667
90 days or greater delinquent	27	477
Business Banking | Other
Loan delinquencies
Recorded investment in loans receivable	65,619	65,189
90 days or greater delinquent	413	1,255
Business Banking | Commercial real estate loans
Loan delinquencies
Recorded investment in loans receivable	1,856,574	1,801,184
90 days or greater delinquent	8,233	11,099
Business Banking | Commercial real estate loans | Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	995,436	1,013,632
90 days or greater delinquent	6,551	8,827
Business Banking | Commercial real estate loans | New York
Loan delinquencies
Recorded investment in loans receivable	662,453	590,934
90 days or greater delinquent	1,242	1,072
Business Banking | Commercial real estate loans | Ohio
Loan delinquencies
Recorded investment in loans receivable	24,751	24,901
Business Banking | Commercial real estate loans | Maryland
Loan delinquencies
Recorded investment in loans receivable	117,092	114,850
90 days or greater delinquent	27	270
Business Banking | Commercial real estate loans | Other
Loan delinquencies
Recorded investment in loans receivable	56,842	56,867
90 days or greater delinquent	413	930
Business Banking | Commercial loans
Loan delinquencies
Recorded investment in loans receivable	368,725	358,376
90 days or greater delinquent	1,921	3,475
Business Banking | Commercial loans | Pennsylvania
Loan delinquencies
Recorded investment in loans receivable	284,442	243,159
90 days or greater delinquent	1,921	2,659
Business Banking | Commercial loans | New York
Loan delinquencies
Recorded investment in loans receivable	55,009	83,252
90 days or greater delinquent		284
Business Banking | Commercial loans | Ohio
Loan delinquencies
Recorded investment in loans receivable	15,991	15,826
Business Banking | Commercial loans | Maryland
Loan delinquencies
Recorded investment in loans receivable	4,506	7,817
90 days or greater delinquent		207
Business Banking | Commercial loans | Other
Loan delinquencies
Recorded investment in loans receivable	8,777	8,322
90 days or greater delinquent		$ 325