Investment securities (Details 5) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Due within 1 year Amortized Cost	$ 18,960
After 1 year but within 5 years Amortized Cost	15,153
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount	34,113
Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value	19,014
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	15,135
Held-to-maturity Securities, Debt Maturities, Fair Value	$ 34,149	$ 26,637

Amount of held-to-maturity debt securities at fair value maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year.

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-Name Accounting Standards Codification

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Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments, maturing in the next fiscal year through the fifth fiscal year following the latest fiscal year.

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This item represents the total of all debt securities grouped by maturity dates, at fair value, which are categorized as held-to-maturity.

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Amount of held-to-maturity debt securities at fair value maturing in the next fiscal year following the latest fiscal year.

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