|
Loans and reserve for credit losses (Troubled Debt Restructurings on Financing Receivables) (Details) (USD $)
In Thousands, unless otherwise specified
|
12 Months Ended |
|
Dec. 31, 2014
loan
|
Dec. 31, 2013
loan
|
Dec. 31, 2012
loan
|
| Troubled Debt Restructuring, Debtor, Current Period [Line Items] |
|
|
|
| Number of loans |
0 |
10 |
110 |
| TDR outstanding recorded investment |
$ 0 |
$ 30,157 |
$ 11,904 |
| Commercial real estate |
|
|
|
| Troubled Debt Restructuring, Debtor, Current Period [Line Items] |
|
|
|
| Number of loans |
0 |
5 |
5 |
| TDR outstanding recorded investment |
0 |
27,677 |
1,761 |
| Construction |
|
|
|
| Troubled Debt Restructuring, Debtor, Current Period [Line Items] |
|
|
|
| Number of loans |
0 |
1 |
6 |
| TDR outstanding recorded investment |
0 |
1,243 |
4,832 |
| Residential real estate |
|
|
|
| Troubled Debt Restructuring, Debtor, Current Period [Line Items] |
|
|
|
| Number of loans |
0 |
0 |
12 |
| TDR outstanding recorded investment |
0 |
0 |
678 |
| Commercial and industrial |
|
|
|
| Troubled Debt Restructuring, Debtor, Current Period [Line Items] |
|
|
|
| Number of loans |
0 |
4 |
32 |
| TDR outstanding recorded investment |
0 |
1,237 |
3,980 |
| Consumer |
|
|
|
| Troubled Debt Restructuring, Debtor, Current Period [Line Items] |
|
|
|
| Number of loans |
0 |
0 |
55 |
| TDR outstanding recorded investment |
$ 0 |
$ 0 |
$ 653 |