Fair Value - Changes in Fair Value for Items Measured at Fair Value Pursuant to Election of the Fair Value (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Schedule of Trading Securities and Other Trading Assets [Line Items]
Interest Income	$ 130,842	$ 108,478	$ 391,377	$ 318,612
Interest (Expense)	(24,527)	(15,047)	(65,434)	(41,590)
Residential Loans Held for Sale [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other Gains and (Losses)	(368)	58	54	755
Interest Income	3		6	2
Interest (Expense)			(4)
Total Changes in Fair Values Included in Current Period Earnings	$ (365)	$ 58	$ 56	$ 757

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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Amount of the cost of borrowed funds accounted for as interest expense.

+ References

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The net amount of operating interest income (expense).

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Amount of gain (loss) related to nonoperating activities, classified as other.

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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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No definition available.

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