Loans and reserve for credit losses (Loans and Leases Receivable, Allowance, Covered) (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended
Jun. 30, 2014
Loans and Leases Receivable, Covered [Roll Forward]
Balance at May 16, 2014	$ 1,035
Charge-off receivable	(2)
Recovery payable	250
Balance at end of period	$ 1,283

Amount of allowance for loan and lease losses covered by loss sharing agreements.

No definition available.

Name:	us-gaap_LoansAndLeasesReceivableAllowanceCovered
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant