Note Transfers of financial assets and servicing assets (Changes in MSRs measured using the fair value method) (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Transfers and Servicing of Financial Assets
Fair value at beginning of period		$ 169,777	$ 168,031
Additions		1,861	2,557
Changes due to payments of loans	[1]	(2,587)	(3,335)
Reduction due to loan repurchases		(491)	(972)
Changes in fair value due to changes in valuation model inputs or assumptions		(747)	0
Fair value at end of period		$ 167,813	$ 166,281

[1] Represents changes due to collection / realization of expected cash flows over time.