Tax Credit Investments Tax Credit Investments - Affordable Housing Tax Credit Investments, Other Tax Credit Investments, and Related Unfunded Commitments (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Assets [Member]
Other Assets [Abstract]
Affordable housing tax credit investments, net	$ 32,094	$ 36,009
Other tax credit investments, net	70,681	66,023
Total tax credit investments, net	102,775	102,032
Other Liabilities
Other Liabilities [Abstract]
Unfunded affordable housing tax credit commitments	7,330	8,800
Unfunded other tax credit commitments	12,545	418
Total unfunded tax credit commitments	$ 19,875	$ 9,218