Note Loans - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	$ 177,090	$ 172,118
Loans and Leases Receivable, Gross, Carrying Amount, Covered	551,980		$ 572,878
GNMA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	147,000	134,000
FNMA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	28,000	36,000
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential Mortgage Loans Sold	28,000	21,000
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans	42,000	106,000
Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans	136,000	122,000
Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans		$ 51,000
Leasing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans	2,000
Westernbank Puerto Rico | ASC Subtopic 310-30
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance of SOP loans	2,100,000		2,100,000
Westernbank Puerto Rico | ASC Subtopic 310-20
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	10,000		10,000
SOP Other Loans Acquired | ASC Subtopic 310-30
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance of SOP loans	$ 689,000		$ 700,000