Quarterly report pursuant to Section 13 or 15(d)

Revolving Credit Facilities (Details)

v3.10.0.1
Revolving Credit Facilities (Details) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2018
Dec. 31, 2017
Short-term Debt [Line Items]    
Revolving credit facilities $ 310,000 $ 20,000
Weighted average borrowing rate 5.36% 5.14%
Weighted average remaining maturity 4 years 5 months 8 days 11 months 15 days
Mortgage servicing rights, at fair value, pledged as collateral for borrowings $ 1,200,000 $ 600,000
Short-term Debt [Member]    
Short-term Debt [Line Items]    
Mortgage servicing rights, at fair value, pledged as collateral for borrowings $ 488,500 $ 159,500