Fair Value Measurements (Details 3)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Information regarding the initial and ending capitalization rate of MSRs
Initial capitalization rate of additions to MSRs (as a percent)	1.09%		1.10%
Capitalization servicing rate (as a percent)	0.93%	0.99%
Capitalization servicing multiple (as a percent)	3.20%	3.40%
Weighted-average servicing fee (in basis points)	0.0029	0.0029
Mortgage servicing rights
Significant assumptions used in estimating fair value
Weighted-average prepayment speed (CPR) (as a percent)	10.30%	9.00%
Option adjusted spread, in basis points (OAS) (as a percent)	8.98%	10.56%
Weighted-average delinquency rate (as a percent)	5.50%	5.80%