Commitments and Contingencies (Details) (USD $)	6 Months Ended	12 Months Ended	6 Months Ended		6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Citizens Financial Group [Member]	Mar. 31, 2009 Citizens Financial Group [Member]	Jun. 30, 2011 Monroe Bancorp [Member]
Sale leaseback transaction, number of units	4
Sale leaseback transaction, financial centers	88
Sale leaseback transaction, carrying value of properties sold	$ 163,600,000
Sale leaseback transaction, gain on sale	123,900,000
Sale leaseback transaction, cash proceeds net of selling costs	287,400,000
Sale leaseback transaction, gain recognized over lease term	119,500,000
Sale leaseback transaction, deferred gain recognized	24,300,000
Lease term, minimum, in years	5		1		1
Lease term, maximum, in years	24		10		5
Additional successive terms extendable at the option	4
Period of extendable lease term, in years	5
Base rent per year	25,400,000		2,200,000		300,000
Number of leased locations acquired				65	2
Number of leased locations closed			24
Number of leased operations centers acquired					1
Number of leased ATM locations acquired					5
Number of retirement centers					3
Loan commitments	1,049,000,000	1,106,000,000
Fixed rate loan commitment	1,011,000,000
Floating rate loan commitment	38,000,000
Standby letters of credit	73,700,000	74,300,000
Loan commitments fixed interest rate, minimum	0.00%
Loan commitments fixed interest rate, maximum	13.25%
Allowance for unfunded loan commitments	3,300,000	3,800,000
Extended credit	25,600,000	25,700,000
Credit extensions with collateral	$ 18,900,000	$ 20,200,000