Quarterly report pursuant to Section 13 or 15(d)

Fair Value, Measurement Inputs, Disclosure (Details)

v3.8.0.1
Fair Value, Measurement Inputs, Disclosure (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Mar. 31, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Available-for-sale Securities Categorized as Level 2 Assets 99.27147%      
Available-for-sale Securities Categorized as Level 3 Assets 0.70%      
Assets Reported at Fair Value, Available-for-sale Securities 92.80%      
Mortgage Servicing Rights Categorized as Level 3 Assets 100.00%      
Mortgage Loans Held-for-sale Categorized as Level 2 Assets 1.60%      
Mortgage Loans Held-for-sale Categorized as Level 3 Assets 98.40%      
Interest Rate Swaps, Swaptions and Credit Default Swaps Categorized as Level 2 Assets (Liabilities) 100.00%      
Inverse Interest-only Securities Categorized as Level 2 Assets 100.00%      
Agency To-be-Announced Securities Categorized as Level 1 Assets (Liabilities) 100.00%      
Mortgage servicing rights $ 1,301,023 $ 1,086,717 $ 747,580 $ 693,815
Derivative assets, at fair value 274,048 309,918    
Equity securities 27,423 29,413    
Derivative liabilities, at fair value 46,074 31,903    
Fair Value, Measurements, Recurring [Member]        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Available-for-sale securities 21,059,377 21,220,819    
Mortgage servicing rights 1,301,023 1,086,717    
Residential mortgage loans held-for-sale 29,428 30,414    
Derivative assets, at fair value 274,048 309,918    
Equity securities 27,423 29,413    
Total assets 22,691,299 22,677,281    
Derivative liabilities, at fair value 46,074 31,903    
Total liabilities 46,074 31,903    
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Available-for-sale securities 0 0    
Mortgage servicing rights 0 0    
Residential mortgage loans held-for-sale 0 0    
Derivative assets, at fair value 8,117 913    
Equity securities 27,423 29,413    
Total assets 35,540 30,326    
Derivative liabilities, at fair value 19,964 1,930    
Total liabilities 19,964 1,930    
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Available-for-sale securities 20,905,953 21,067,678    
Mortgage servicing rights 0 0    
Residential mortgage loans held-for-sale 470 474    
Derivative assets, at fair value 265,931 309,005    
Equity securities 0 0    
Total assets 21,172,354 21,377,157    
Derivative liabilities, at fair value 26,110 29,973    
Total liabilities 26,110 29,973    
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Available-for-sale securities 153,424 153,141    
Mortgage servicing rights 1,301,023 1,086,717    
Residential mortgage loans held-for-sale 28,958 29,940    
Derivative assets, at fair value 0 0    
Equity securities 0 0    
Total assets 1,483,405 1,269,798    
Derivative liabilities, at fair value 0 0    
Total liabilities $ 0 $ 0