Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Fair Value, Measurements, Nonrecurring [Member]	Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member]	Jun. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Jun. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Significant Other Observable Inputs (Level 2) [Member]	Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Significant Other Observable Inputs (Level 2) [Member]	Jun. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Significant Unobservable Inputs (Level 3) [Member]	Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Significant Unobservable Inputs (Level 3) [Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements for items measured at fair value
Available for sale securities											$ 672,809	$ 562,691	$ 101	$ 1,714	$ 672,708	$ 560,977	$ 0	$ 0
Loans available for sale											26,029	11,186	0	0	26,029	11,186	0	0
Loans			20,691	34,468	0	0	11,048	12,802	9,643	21,666
Other real estate owned	$ 10,063	$ 11,887	$ 10,063	$ 7,219	$ 0	$ 0	$ 2,022	$ 1,783	$ 8,041	$ 5,436