Derivative Financial Instruments (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Other Income [Member]
Derivative [Line Items]
Gain recognized in income, net of tax	$ 0		$ 46,000		$ 0		$ 102,000
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Impact on interest expense, decrease (increase)			(229,000,000)				(454,300,000)
Fair value			1,600,000				1,600,000
Gain (loss) recognized in income							169,000,000
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) recognized in income	177,000		0		177,000		11,000
Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Gain (loss) recognized in income	177,000	[1]	0	[1]	177,000	[1]	55,000	[1]
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in income	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ (44,000)	[1]

[1] For 2011, recognized in "Net loss from discontinued operations" in FNB's Consolidated Statements of Operations.