Regulatory Matters (Schedule of Compliance with Regulatory Capital Requirements Under Banking Regulations) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Consolidated
Total Capital (to Risk Weighted Assets) [Abstract]
Total Capital	$ 2,733,143	$ 2,653,893
Total Capital to Risk Weighted Assets (Ratio)	13.74%	15.26%
Capital Required for Capital Adequacy	$ 1,591,341	$ 1,391,282
Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	8.00%	8.00%
Capital Required to be Well Capitalized	$ 1,989,176	$ 1,739,102
Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	10.00%	10.00%
Tier I Capital (to Average Assets) [Abstract]
Tier One Leverage Capital		$ 2,004,461
Tier One Leverage Capital to Average Assets (Ratio)	8.63%	8.43%
Tier One Leverage Capital Required for Capital Adequacy	$ 981,690	$ 951,430
Tier One Leverage Capital Required for Capital Adequacy to Average Assets (Ratio)	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$ 1,227,113	$ 1,189,287
Tier One Leverage Capital Required to be Well Capitalized to Average Assets (Ratio)	5.00%	5.00%
Bank Only
Total Capital (to Risk Weighted Assets) [Abstract]
Total Capital	$ 2,668,419	$ 2,521,412
Total Capital to Risk Weighted Assets (Ratio)	13.42%	14.49%
Capital Required for Capital Adequacy	$ 1,590,382	$ 1,391,988
Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	8.00%	8.00%
Capital Required to be Well Capitalized	$ 1,987,978	$ 1,739,986
Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	10.00%	10.00%
Tier I Capital (to Average Assets) [Abstract]
Tier One Leverage Capital		$ 2,127,065
Tier One Leverage Capital to Average Assets (Ratio)	9.23%	8.94%
Tier One Leverage Capital Required for Capital Adequacy	$ 980,975	$ 951,455
Tier One Leverage Capital Required for Capital Adequacy to Average Assets (Ratio)	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$ 1,226,219	$ 1,189,319
Tier One Leverage Capital Required to be Well Capitalized to Average Assets (Ratio)	5.00%	5.00%
Basel III \| Consolidated
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier One Risk Based Capital	$ 2,119,025
Tier One Risk Based Capital to Risk Weighted Assets (Ratio)	10.65%
Tier One Risk Based Capital Required for Capital Adequacy	$ 895,129
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	4.50%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,292,964
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	6.50%
Basel III \| Bank Only
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier One Risk Based Capital	$ 2,262,669
Tier One Risk Based Capital to Risk Weighted Assets (Ratio)	11.38%
Tier One Risk Based Capital Required for Capital Adequacy	$ 894,590
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	4.50%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,292,185
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	6.50%
Basel I \| Consolidated
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier One Risk Based Capital	$ 2,119,025	$ 2,004,461
Tier One Risk Based Capital to Risk Weighted Assets (Ratio)	10.65%	11.53%
Tier One Risk Based Capital Required for Capital Adequacy	$ 1,193,506	$ 695,641
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	6.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,591,341	$ 1,043,461
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	8.00%	6.00%
Tier I Capital (to Average Assets) [Abstract]
Tier One Leverage Capital	$ 2,119,025
Basel I \| Bank Only
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier One Risk Based Capital	$ 2,262,669	$ 2,127,065
Tier One Risk Based Capital to Risk Weighted Assets (Ratio)	11.38%	12.22%
Tier One Risk Based Capital Required for Capital Adequacy	$ 1,192,787	$ 695,994
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	6.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,590,382	$ 1,043,991
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	8.00%	6.00%
Tier I Capital (to Average Assets) [Abstract]
Tier One Leverage Capital	$ 2,262,669

Tier I Capital (to Average Assets) [Abstract]

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Tier I Capital (to Risk Weighted Assets) [Abstract]

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Total Capital (to Risk Weighted Assets) [Abstract]

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The amount of total capital as defined in the regulations.

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The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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