Note Other comprehensive income (loss) (Reclassification out of accumulated other comprehensive income (loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassification out of accumulated other comprehensive loss
Personnel costs	$ (143,117)	$ (125,852)
Income tax (benefit) expense	(50,223)	(22,155)
Net Income	167,925	91,324
Reclassification out of accumulated other comprehensive income
Reclassification out of accumulated other comprehensive loss
Net Income	(4,317)	(1,983)
Reclassification out of accumulated other comprehensive income | Adjustment of pension and postretirement benefit plan
Reclassification out of accumulated other comprehensive loss
Income (loss) before tax	(5,876)	(4,519)
Income tax (benefit) expense	2,203	1,763
Net Income	(3,673)	(2,756)
Reclassification out of accumulated other comprehensive income | Adjustment of pension and postretirement benefit plan | Amortization of net losses | Personnel costs
Reclassification out of accumulated other comprehensive loss
Income (loss) before tax	(5,876)	(5,386)
Reclassification out of accumulated other comprehensive income | Adjustment of pension and postretirement benefit plan | Amortization of prior service credit | Personnel costs
Reclassification out of accumulated other comprehensive loss
Income (loss) before tax	0	867
Reclassification out of accumulated other comprehensive income | Unrealized net (losses) gains on cash flow hedges | Forward contracts
Reclassification out of accumulated other comprehensive loss
Income (loss) before tax	(1,030)	1,267
Income tax (benefit) expense	386	(494)
Net Income	(644)	773
Reclassification out of accumulated other comprehensive income | Unrealized net (losses) gains on cash flow hedges | Forward contracts | Mortgage banking activities
Reclassification out of accumulated other comprehensive loss
Income (loss) before tax	$ (1,030)	$ 1,267