Securities Available-for-Sale (Details 2) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
U.S. Government Sponsored Enterprises [Member]
Continuous unrealized loss position for 12 months or less and 12 months or longer
Less than 12 months, Fair Value		$ 14,989
Less than 12 months, Unrealized Losses		11
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Total, Fair Value		14,989
Total, Unrealized Losses		11
U.S. Government Agency and Sponsored Mortgage Backed Securities [Member]
Continuous unrealized loss position for 12 months or less and 12 months or longer
Less than 12 months, Fair Value	52,036	331,469
Less than 12 months, Unrealized Losses	221	1,176
12 months or longer, Fair Value	11,629
12 months or longer, Unrealized Losses	29
Total, Fair Value	63,665	331,469
Total, Unrealized Losses	250	1,176
Privately Issued Residential Mortgage Backed Securities [Member]
Continuous unrealized loss position for 12 months or less and 12 months or longer
12 months or longer, Fair Value	1,939	3,198
12 months or longer, Unrealized Losses	21	311
Total, Fair Value	1,939	3,198
Total, Unrealized Losses	21	311
Obligations Issued by States and Political Subdivisions [Member]
Continuous unrealized loss position for 12 months or less and 12 months or longer
12 months or longer, Fair Value	3,725	3,725
12 months or longer, Unrealized Losses	960	957
Total, Fair Value	3,725	3,725
Total, Unrealized Losses	960	957
Other Debt Securities [Member]
Continuous unrealized loss position for 12 months or less and 12 months or longer
Less than 12 months, Fair Value		10,542
Less than 12 months, Unrealized Losses		652
12 months or longer, Fair Value	1,464	1,468
12 months or longer, Unrealized Losses	36	31
Total, Fair Value	1,464	12,010
Total, Unrealized Losses	36	683
Equity Securities [Member]
Continuous unrealized loss position for 12 months or less and 12 months or longer
Less than 12 months, Fair Value
Less than 12 months, Unrealized Losses
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Total, Unrealized Losses
Temporarily Impaired Investment [Member]
Continuous unrealized loss position for 12 months or less and 12 months or longer
Less than 12 months, Fair Value	52,036	357,000
Less than 12 months, Unrealized Losses	221	1,839
12 months or longer, Fair Value	18,757	8,391
12 months or longer, Unrealized Losses	1,046	1,299
Total, Fair Value	70,793	365,391
Total, Unrealized Losses	$ 1,267	$ 3,138