Goodwill and Intangible Assets - Schedule of Estimated Amortization Expense (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
2017	$ 448
2018	149
2019	126
2020	109
2021	106
Thereafter	694
Estimated amortization expense	1,632	$ 2,242
MSRs [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2017	28
2018	38
2019	38
2020	38
2021	38
Thereafter	497
Estimated amortization expense	677	604
Core deposit intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2017	420
2018	111
2019	88
2020	71
2021	68
Thereafter	197
Estimated amortization expense	$ 955	$ 1,638