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	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule of Trading Securities and Other Trading Assets [Line Items]
Interest Income	$ 131,963	$ 104,333	$ 260,535	$ 210,134
Interest (Expense)	(21,773)	(13,876)	(40,907)	(26,543)
Residential Loans Held for Sale [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other Gains and (Losses)	387	279	422	697
Interest Income	3	1	3	2
Interest (Expense)			(4)
Total Changes in Fair Values Included in Current Period Earnings	$ 390	$ 280	$ 421	$ 699

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.

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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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