Securities (Details 2) (USD $)	Dec. 31, 2013 item	Dec. 31, 2012 item
Securities available for sale, Amortized cost
Due within 1 year	$ 120,183,000
Due after 1 but within 5 years	128,126,000
Due after 5 but within 10 years	35,980,000
Due after 10 years	32,253,000
Mortgage-backed securities	176,524,000
Total securities available for sale	493,066,000
Securities available for sale, Fair value
Due within 1 year	120,234,000
Due after 1 but within 5 years	129,476,000
Due after 5 but within 10 years	36,172,000
Due after 10 years	31,456,000
Mortgage-backed securities	172,693,000
Total securities available for sale, fair value	490,031,000	386,440,000
Carrying value of securities pledged to secure accounts of commercial depositors	$ 243,500,000	$ 158,200,000
Number of holdings that consisted of a security issued by a single institution, except the issue made by US government and its agencies	0	0
Maximum amount of holdings that consisted of a security issued by a single institution, except the issue made by US government and its agencies (as a percent)	10.00%	10.00%