Fair Value Measurements (Valuation Techniques and Unobservable Inputs Used in the Valuation of Financial Instruments Falling within Level 3 of the Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	$ 6,028,334	$ 4,905,436
Private label residential mortgage-backed securities and CMO's - Investment grade | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	3.78%
Probability rate of default	0.03%
Loss severity	0.00%
Fair Value Inputs, Discount Rate	2.41%
Private label residential mortgage-backed securities and CMO's - Investment grade | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	10.57%
Probability rate of default	12.39%
Loss severity	22.58%
Fair Value Inputs, Discount Rate	6.67%
Private label residential mortgage-backed securities and CMO's - Investment grade | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	8.44%
Probability rate of default	2.54%
Loss severity	1.91%
Fair Value Inputs, Discount Rate	3.44%
Private label residential mortgage-backed securities and CMO's - Non-investment grade | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	4.66%
Probability rate of default	0.02%
Loss severity	0.00%
Fair Value Inputs, Discount Rate	2.80%
Private label residential mortgage-backed securities and CMO's - Non-investment grade | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	13.78%
Probability rate of default	8.08%
Loss severity	7.32%
Fair Value Inputs, Discount Rate	18.29%
Private label residential mortgage-backed securities and CMO's - Non-investment grade | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	8.00%
Probability rate of default	2.19%
Loss severity	1.29%
Fair Value Inputs, Discount Rate	5.13%
Private label residential mortgage-backed securities and CMO's - Option-arm | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	2.91%
Probability rate of default	3.90%
Loss severity	12.78%
Fair Value Inputs, Discount Rate	3.50%
Private label residential mortgage-backed securities and CMO's - Option-arm | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	2.97%
Probability rate of default	8.86%
Loss severity	18.77%
Fair Value Inputs, Discount Rate	33.43%
Private label residential mortgage-backed securities and CMO's - Option-arm | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	2.92%
Probability rate of default	7.62%
Loss severity	14.28%
Fair Value Inputs, Discount Rate	8.97%
Residential Servicing Rights [Member] [Member] | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	6.11%
Fair Value Inputs, Discount Rate	9.13%
Residential Servicing Rights [Member] [Member] | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	23.18%
Fair Value Inputs, Discount Rate	9.19%
Residential Servicing Rights [Member] [Member] | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	13.15%
Fair Value Inputs, Discount Rate	9.14%
Commercial Servicing Rights [Member] [Member] | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	1.34%
Fair Value Inputs, Discount Rate	8.99%
Commercial Servicing Rights [Member] [Member] | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	9.77%
Fair Value Inputs, Discount Rate	13.58%
Commercial Servicing Rights [Member] [Member] | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	7.39%
Fair Value Inputs, Discount Rate	11.88%
Fair Value, Inputs, Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	$ 156,343	$ 156,967
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Investment grade
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	57,012
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Non-investment grade
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	40,824
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Option-arm
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	29,467
Fair Value, Inputs, Level 3 | Residential Servicing Rights [Member] [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	13,122
Fair Value, Inputs, Level 3 | Commercial Servicing Rights [Member] [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	$ 11,594