FIRST BANCORP. (Holding Company Only) Financial Information - Statements of Financial Condition (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
ASSETS
Cash and due from banks	$ 953,038	$ 454,302
Money market investments	16,957	201,369	201,365
Investment securities available for sale, at market:
Other investment securities	944,670	935,800
Loans Receivable, net	9,169,982	9,426,281
Other assets	171,179	179,570
Total assets	12,643,280	12,656,925
Liabilities:
Other borrowings	231,959	231,959
Accounts payable and other liabilities	158,990	129,184
Total liabilities	11,319,123	11,441,067
Stockholders Equity	1,324,157	1,215,858	1,220,593
Total liabilities and stockholders' equity	12,643,280	12,656,925
Investment In Banking Subsidiary [Member]
Investment securities available for sale, at market:
Equity Method Investments	1,516,603	1,403,612
Non Banking Subsidiary [Member]
Investment securities available for sale, at market:
Equity Method Investments	11,537	9,834
Statutory Trust One [Member]
Investment securities available for sale, at market:
Equity Method Investments	3,093	3,093
Statutory Trust Two [Member]
Investment securities available for sale, at market:
Equity Method Investments	3,866	3,866
Holding Company [Member]
ASSETS
Cash and due from banks	29,990	31,957
Money market investments	6,111	6,111
Investment securities available for sale, at market:
Equity Investments	14	33
Other investment securities	285	285
Loans Receivable, net	333	356
Other assets	4,683	4,101
Total assets	1,576,515	1,463,248
Liabilities:
Other borrowings	231,959	231,959
Accounts payable and other liabilities	20,399	15,431
Total liabilities	252,358	247,390
Stockholders Equity	1,324,157	1,215,858
Total liabilities and stockholders' equity	$ 1,576,515	$ 1,463,248