Discounts for Collateral Value Estimates Due to Estimated Holding and Selling Costs (Percent)

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

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-Publisher FASB
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-Topic 820
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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

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Amount of transfers of liabilities measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

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Amount of transfers of liabilities measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

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Amount of transfers of financial instrument classified as a liability into level 3 of the fair value hierarchy.

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For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

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Fair value of financial and nonfinancial obligations.

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-Publisher FASB
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-Topic 820
-SubTopic 10
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Estimated Fair Values (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	$ 4,783,507		$ 4,783,507		$ 7,180,180
Liability transfers between Level 1 and Level 2	0		0		0
Asset transfers between Level 1 and Level 2	0		0		0
Liability transfers between Level 2 and Level 1	0		0		0
Asset transfers between Level 2 and Level 1	0		0		0
Gains (Losses) from fair value changes on originated loans held for sale	700	$ 291	245	$ 3,452
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability measured at fair value on nonrecurring basis	$ 0		$ 0		$ 0
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounts for collateral value estimates due to estimated holding and selling costs (percent)	6.00%		6.00%		6.00%
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounts for collateral value estimates due to estimated holding and selling costs (percent)	11.00%		11.00%		11.00%
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3			$ 59,700
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3			$ 5,600