First Financial Holdings, Inc. (Parent Company Only) Condensed Financial Information (Detail) - Schedule of Condensed Statement of Operations (USD $) In Thousands, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Sep. 30, 2011	Sep. 30, 2010
Income
Interest income					$ 293				$ 683
Total income					10,252					28,973	(43,560)	(35,872)
Expenses
Interest expense	6,460	6,817	7,630	8,107	8,713	9,492	10,056	10,897		29,014	42,269	54,322
Salaries and employee benefits					14,511				15,498	61,995	62,981	58,496
Loss before income taxes and equity in undistributed (losses) earnings of subsidiaries					25,338	4,774	(65,564)	(2,278)
Income tax benefit	(3,921)	(3,516)	(7,712)	(4,241)	(9,766)				(636)	(19,390)	17,123	24,388
Net income (loss)	7,823	6,667	12,584	1,739	15,572	1,077	(43,000)	(430)	1,167	28,813	(41,186)	(36,789)
Preferred stock dividends					813				813	3,250	3,250	3,252
Accretion on preferred stock discount					153				144	637	591	556
Net income (loss) available to common shareholders	6,848	5,694	11,614	770	14,606	113	(43,961)	(1,389)	210	24,926	(41,462)	(43,116)
Parent [Member]
Income
Dividend income					0					0	0	0
Interest income					40					86	179	432
Other income					35					0	276	351
Total income					75					86	455	783
Expenses
Interest expense					787					3,150	3,150	3,226
Salaries and employee benefits					216					377	1,624	2,190
Shareholder relations and other expense					352					2,736	2,193	1,741
Total expense					1,355					6,263	6,967	7,157
Loss before income taxes and equity in undistributed (losses) earnings of subsidiaries					(1,280)					(6,177)	(6,512)	(6,374)
Income tax benefit					(420)					(1,275)	(2,142)	(2,538)
Loss before equity in undistributed losses of subsidiaries					(860)					(4,902)	(4,370)	(3,836)
Equity in undistributed earnings (losses) of subsidiaries					16,432					33,715	(36,816)	(32,953)
Net income (loss)					15,572					28,813	(41,186)	(36,789)
Preferred stock dividends					813					3,250	3,250	3,252
Accretion on preferred stock discount					153					637	591	556
Net income (loss) available to common shareholders					$ 14,606					$ 24,926	$ (45,027)	$ (40,597)