Quarterly report pursuant to Section 13 or 15(d)

Commercial Real Estate Assets by Geographic Location (Details)

v3.8.0.1
Commercial Real Estate Assets by Geographic Location (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Jun. 30, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Commercial real estate assets $ 2,171,344 $ 1,782,749 $ 1,412,543 $ 1,114,548 $ 926,377 $ 660,953
Percentage of Commercial Portfolio 100.00%   100.00%      
United States, Northeastern Region [Member]            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Commercial real estate assets $ 924,383   $ 578,762      
Percentage of Commercial Portfolio 42.60%   41.00%      
United States, Western Region [Member]            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Commercial real estate assets $ 414,612   $ 250,044      
Percentage of Commercial Portfolio 19.10%   17.70%      
United States, Southwestern Region [Member]            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Commercial real estate assets $ 363,907   $ 267,944      
Percentage of Commercial Portfolio 16.80%   19.00%      
United States, Southeastern Region [Member]            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Commercial real estate assets $ 350,407   $ 239,194      
Percentage of Commercial Portfolio 16.10%   16.90%      
United States, Midwestern Region [Member]            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Commercial real estate assets $ 118,035   $ 76,599      
Percentage of Commercial Portfolio 5.40%   5.40%