Fair Value Qualitative information about Level 3 fair value measurements (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	$ 4,987,311	$ 5,014,285
Impaired Loan Fair Value	9,200	9,496
Other Assets, Fair Value Disclosure	4,966,414	4,997,318
Loans Held-for-sale, Fair Value Disclosure	11,517	7,306
Fair Value, Measurements, Nonrecurring [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	9,200	9,496
Other Assets, Fair Value Disclosure	8,642	8,515
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	9,200	9,496
Other Assets, Fair Value Disclosure	8,642	8,515
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Assets, Fair Value Disclosure	3,345	3,387
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Assets, Fair Value Disclosure	3,345	3,387
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	3,370	3,698
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	$ 3,370	3,698
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loan Fair Value		$ 3,698
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Minimum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	0.00%	0.00%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	7.00%	7.00%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Minimum [Member] | Cost Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Accumulated Depreciation	20.00%	50.00%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Maximum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	45.90%	45.90%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	13.30%	13.30%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Maximum [Member] | Cost Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Accumulated Depreciation	50.00%	50.00%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Weighted Average [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	15.80%	20.30%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Weighted Average [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	10.00%	9.50%
Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Weighted Average [Member] | Cost Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Accumulated Depreciation	46.30%	50.00%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Loans Receivable [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loan Fair Value		$ 2,044
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Loans Receivable [Member] | Minimum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	5.00%	5.00%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Loans Receivable [Member] | Minimum [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	10.70%	10.70%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Loans Receivable [Member] | Maximum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	40.00%	40.00%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Loans Receivable [Member] | Maximum [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	10.70%	10.70%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Loans Receivable [Member] | Weighted Average [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	22.10%	22.10%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Loans Receivable [Member] | Weighted Average [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	10.70%	10.70%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate - Remaining Commercial [Member] | Loans Receivable [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loan Fair Value		$ 1,872
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate - Remaining Commercial [Member] | Loans Receivable [Member] | Minimum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	0.00%	0.00%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate - Remaining Commercial [Member] | Loans Receivable [Member] | Minimum [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	10.00%	10.00%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate - Remaining Commercial [Member] | Loans Receivable [Member] | Maximum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	25.30%	25.30%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate - Remaining Commercial [Member] | Loans Receivable [Member] | Maximum [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	10.70%	10.70%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate - Remaining Commercial [Member] | Loans Receivable [Member] | Weighted Average [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	1.00%	1.00%
Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate - Remaining Commercial [Member] | Loans Receivable [Member] | Weighted Average [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	10.00%	10.00%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Assets, Fair Value Disclosure	$ 2,000	$ 2,332
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Assets, Fair Value Disclosure	$ 2,000	2,332
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loan Fair Value		$ 1,882
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Minimum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	0.00%	0.00%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	3.80%	3.80%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Minimum [Member] | Cost Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Accumulated Depreciation	50.00%	33.30%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Maximum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	45.00%	96.70%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	10.10%	10.10%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Maximum [Member] | Cost Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Accumulated Depreciation	50.00%	50.00%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Weighted Average [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	14.20%	12.50%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Weighted Average [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	9.40%	9.10%
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Loans Receivable [Member] | Weighted Average [Member] | Cost Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Accumulated Depreciation	50.00%	43.40%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Commercial [Member] | Minimum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	0.00%	2.00%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Commercial [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	9.50%	9.50%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Commercial [Member] | Maximum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	71.00%	71.00%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Commercial [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	9.50%	9.50%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Commercial [Member] | Real Estate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Assets, Fair Value Disclosure	$ 3,297	$ 2,796
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Commercial [Member] | Real Estate [Member] | Weighted Average [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	23.10%	26.90%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Commercial [Member] | Real Estate [Member] | Weighted Average [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Cap Rate	9.50%	9.50%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Construction [Member] | Minimum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	0.00%	0.00%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Construction [Member] | Minimum [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	15.00%	15.00%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Construction [Member] | Maximum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	85.00%	85.00%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Construction [Member] | Maximum [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	15.00%	15.00%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Construction [Member] | Real Estate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Assets, Fair Value Disclosure	$ 3,345	$ 3,387
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Construction [Member] | Real Estate [Member] | Weighted Average [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	24.40%	24.30%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Construction [Member] | Real Estate [Member] | Weighted Average [Member] | Bulk Sale Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	15.00%	15.00%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Residential [Member] | Minimum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	0.10%	0.10%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Residential [Member] | Maximum [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	61.80%	61.80%
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Residential [Member] | Real Estate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Assets, Fair Value Disclosure	$ 2,000	$ 2,332
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned, Residential [Member] | Real Estate [Member] | Weighted Average [Member] | Sales Comparison Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	22.90%	23.00%
Construction Real Estate, SEPH Commercial Land and Development [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	$ 2,043	$ 2,044
Construction Real Estate, SEPH Commercial Land and Development [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	2,043	2,044
Construction Real Estate - Remaining Commercial [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	1,976	1,872
Construction Real Estate - Remaining Commercial [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	1,976	1,872
Fair Value [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired Loan Fair Value		$ 9,496
Fair Value [Member] | Fair Value, Measurements, Nonrecurring [Member] | Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	3,370
Fair Value [Member] | Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	1,811
Fair Value [Member] | Construction Real Estate, SEPH Commercial Land and Development [Member] | Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	2,043
Fair Value [Member] | Construction Real Estate - Remaining Commercial [Member] | Fair Value, Measurements, Nonrecurring [Member] | Construction Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	$ 1,976