Derivatives and Financial Instruments (Gain/(Loss), Net of Tax Recognized in Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Designated as hedges [Member] | Interest rate swap contracts [Member] | FHLB advance [Member] | Other income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of tax recognized in income	$ 0		$ 819		$ 165
Not designated as hedges [Member] | Continuing operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of tax recognized in income	204		11		168
Not designated as hedges [Member] | Continuing operations [Member] | Mortgage loan rate lock commitments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of tax recognized in income	152	[1]	55	[1]	251	[1]
Not designated as hedges [Member] | Continuing operations [Member] | Mortgage loan forward sales and MBS [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of tax recognized in income	52	[1]	(44)	[1]	(83)	[1]
Not designated as hedges [Member] | Discontinued operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of tax recognized in income	0		(44)		(179)
Not designated as hedges [Member] | Discontinued operations [Member] | Mortgage loan rate lock commitments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of tax recognized in income	0	[2]	0	[2]	28	[2]
Not designated as hedges [Member] | Discontinued operations [Member] | Mortgage loan forward sales and MBS [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss), net of tax recognized in income	$ 0	[2]	$ (44)	[2]	$ (207)	[2]

[1] For 2011 and 2010, recognized in "Net loss from discontinued operations" in FNB's Consolidated Statements of Operations.

[2] Recognized in “Net loss from discontinued operations” in the Company’s Consolidated Statements of Operations.