Goodwill and other intangible assets - Additional Information (Detail) - Entity [Domain] - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Line Items]
Indefinite Lived Intangible Assets	$ 6,000,000		$ 6,000,000			$ 6,000,000
Amortization Of Intangible Assets			4,985,000	$ 5,007,000
Goodwill Written Off Related To Business Unit To Be Disposed				(186,511,000)
Goodwil, Acquired During Period			42,634,000	0
Goodwill Purchase Accounting Adjustments			(2,875,000)	0
FDIC Assisted Partial Acquisition Of Doral Bank [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangible Assets Other Than Goodwill					$ 23,572,000
Banco Popular De Puerto Rico [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwill Written Off Related To Business Unit To Be Disposed				0
Goodwil, Acquired During Period			3,899,000	0
Goodwill Purchase Accounting Adjustments			(2,875,000)	0
Banco Popular De Puerto Rico [Member] | FDIC Assisted Partial Acquisition Of Doral Bank [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwil, Acquired During Period			3,400,000
Goodwill Purchase Accounting Adjustments			500,000
Banco Popular De Puerto Rico [Member] | Insurance benefits business acquisition [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwill Purchase Accounting Adjustments			2,300,000
Banco Popular North America [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwill Written Off Related To Business Unit To Be Disposed				(186,511,000)
Goodwil, Acquired During Period			38,735,000	0
Goodwill Purchase Accounting Adjustments			0	0
Segment, Discontinued Operations [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwill Written Off Related To Business Unit To Be Disposed	0	$ 186,511,000	0	186,511,000
Segment, Continuing Operations [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Amortization Of Intangible Assets	$ 2,881,000	$ 2,025,000	$ 4,985,000	$ 4,051,000
Fully Amortized Intangibles [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Finite-Lived Core Deposits, Gross					$ 27,000,000