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
	Mar. 31, 2020	Mar. 31, 2019
Schedule of Trading Securities and Other Trading Assets [Line Items]
Interest income (expense)	$ 143,771	$ 147,048
Interest (Expense)	(24,228)	(31,870)
Residential loans held for sale
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other Gains and (Losses)	1,421	90
Interest income (expense)	2	5
Interest (Expense)	0	0
Total Changes in Fair Values Included in Current Period Earnings	$ 1,423	$ 95