Trust preferred securities - Additional Information (Detail) (USD $)	Sep. 30, 2014	Jun. 30, 2014 Popular Capital Trust I I I [Member]	Dec. 31, 2013 Popular Capital Trust I I I [Member] Trust Preferred Securities Subject To Mandatory Redemption [Member]		Jun. 30, 2014 Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]	Dec. 31, 2013 Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Debt Disclosure [Line Items]
Maximum Percentage Of Restricted Core Capital To All Core Capital That May Be Included In Tier One Capital	25.00%
Trust Preferred Securities Subject To Phase Out Provision Of Dodd Frank Act	$ 427,000,000
Percent Of Non Qualifying Capital Instruments Allowed For Tier I Capital In 2015	25.00%
Percent Of Non Qualifying Capital Instruments Allowed For Tier I Capital In 2016	0.00%
Debt Instrument Unamortized Discount						404,460,000
Trust Preferred Securities		935,000,000	935,000,000	[1],[2],[3],[4]
Debt Instrument Unamortized Discount And Fee Amount					414,100,000
Amount Of Trust Preferred Securities That Exceeds Core Capital Elements Limitation	0
Common securities			1,000,000	[1],[2],[3],[4]
Debt Instrument Carrying Amount			936,000,000	[1],[2],[3],[4]		936,000,000
Liquidation Amount Of Capital Securities	$ 1,000

[1] Statutory business trust that is wholly-owned by the Corporation.

[2] These capital securities are fully and unconditionally guaranteed on a subordinated basis by the Corporation to the extent set forth in the applicable guarantee agreement.

[3] The debentures are perpetual and may be redeemed by Popular at any time, subject to the consent of the Board of Governors of the Federal Reserve System.

[4] Carrying value of junior subordinated debentures of $ 532 million at December 31, 2013 ($ 936 million aggregate liquidation amount, net of $ 404 million discount).