Fair Value of Financial Instruments Table of Significant Observable Inputs used in the Valuation of Level 3 Assets(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	$ 5,013	$ 35,281
Loans Receivable, Fair Value Disclosure	258,173	373,089
Significant unobservable inputs Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total	$ 42,474	$ 79,795
Significant unobservable inputs Level 3 | Interest Rate Lock Commitments | Internal Model | Minimum
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Fair Value Assumptions, Pull Through Rate	50.00%	45.00%
Significant unobservable inputs Level 3 | Interest Rate Lock Commitments | Internal Model | Maximum
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Fair Value Assumptions, Pull Through Rate	95.00%	95.00%
Recurring | Significant unobservable inputs Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total	$ 162,666	$ 797,062
Non-Collateralized Loans Obligations | Recurring | Significant unobservable inputs Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	4,808	4,872
Loans Receivable, Fair Value Disclosure	154,402	205,298
Total		211,192
Non-Collateralized Loans Obligations | Recurring | Significant unobservable inputs Level 3 | Interest Rate Lock Commitments
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		4,872
Non-Collateralized Loans Obligations | Recurring | Significant unobservable inputs Level 3 | Interest Rate Lock Commitments | Internal Model
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	4,808	4,872
Non-Collateralized Loans Obligations | Recurring | Significant unobservable inputs Level 3 | Nonperforming Financial Instruments
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure		74,923
Non-Collateralized Loans Obligations | Recurring | Significant unobservable inputs Level 3 | Nonperforming Financial Instruments | Cash Flow Model
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	$ 37,666	$ 74,923