Deposits (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Certificates of deposit
2013, Weighted Average Rate (as a percent)	0.85%
2014, Weighted Average Rate (as a percent)	1.63%
2015, Weighted Average Rate (as a percent)	2.31%
2016, Weighted Average Rate (as a percent)	2.18%
2017, Weighted Average Rate (as a percent)	1.19%
2018 and thereafter, Weighted Average Rate (as a percent)	2.01%
Total, Weighted Average Rate (as a percent)	1.55%
2013, Balance	$ 1,502,496
2014, Balance	871,751
2015, Balance	988,548
2016, Balance	451,875
2017, Balance	145,381
2018 and thereafter, Balance	320
Total, Balance	$ 3,960,371	$ 5,519,007
2013 (as a percent)	37.94%
2014 (as a percent)	22.01%
2015 (as a percent)	24.96%
2016 (as a percent)	11.41%
2017 (as a percent)	3.67%
2018 and thereafter (as a percent)	0.01%
Percent of total	100.00%