Fair Value Measurements Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Inputs - Quoted Prices in Active Markets for Identical Assets, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	$ 0	$ 0
Fair Value, Significant Other observable Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	117,284	172,040
Fair Value, Significant Unobservable Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Mortgage Loans Held for Sale [Member] | Fair Value, Inputs - Quoted Prices in Active Markets for Identical Assets, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Mortgage Loans Held for Sale [Member] | Fair Value, Significant Other observable Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	115,189	171,580
Mortgage Loans Held for Sale [Member] | Fair Value, Significant Unobservable Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Forward Sales of Mortgage Backed Securities [Member] | Fair Value, Inputs - Quoted Prices in Active Markets for Identical Assets, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Forward Sales of Mortgage Backed Securities [Member] | Fair Value, Significant Other observable Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	1,624	177
Forward Sales of Mortgage Backed Securities [Member] | Fair Value, Significant Unobservable Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Interest Rate Lock Commitments [Member] | Fair Value, Inputs - Quoted Prices in Active Markets for Identical Assets, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Interest Rate Lock Commitments [Member] | Fair Value, Significant Other observable Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	384	271
Interest Rate Lock Commitments [Member] | Fair Value, Significant Unobservable Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Whole Loan Contracts [Member] | Fair Value, Inputs - Quoted Prices in Active Markets for Identical Assets, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Whole Loan Contracts [Member] | Fair Value, Significant Other observable Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	87	12
Whole Loan Contracts [Member] | Fair Value, Significant Unobservable Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	0	0
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	117,284	172,040
Fair Value, Measurements, Recurring [Member] | Mortgage Loans Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	115,189	171,580
Fair Value, Measurements, Recurring [Member] | Forward Sales of Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	1,624	177
Fair Value, Measurements, Recurring [Member] | Interest Rate Lock Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	384	271
Fair Value, Measurements, Recurring [Member] | Whole Loan Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities) at Fair Value	$ 87	$ 12