Shareholders' Equity, Dividend Restrictions and Other Regulatory Matters (Detail) - Schedule of Capital Amounts and Ratios (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Sep. 30, 2011
First Financial1
Core capital to Total Assets	$ 337,908	[1]
Core capital to Total Assets	10.54%	[1]
Core capital to Total Assets	128,287	[1]
Core capital to Total Assets	4.00%	[1]
Tier I capital to Risk-based Assets	337,908	[1]
Tier I capital to Risk-based Assets	14.89%	[1]
Tier I capital to Risk-based Assets	90,804	[1]
Tier I capital to Risk-based Assets	4.00%	[1]
Tier I capital to Risk-based Assets	0	[1]
Risk-based capital to Risk-based Assets	366,897	[1]
Risk-based capital to Risk-based Assets	16.16%	[1]
Risk-based capital to Risk-based Assets	181,608	[1]
Risk-based capital to Risk-based Assets	8.00%	[1]
Risk-based capital to Risk-based Assets	0	[1]
As Recorded By First Federal [Member]
First Financial1
Core capital to Total Assets	319,555	[2]	279,947	[2]	263,410	[2]
Core capital to Total Assets	9.97%	[2]	8.92%	[2]	8.26%	[2]
Core capital to Total Assets	128,201	[2]	125,553	[2]	127,615	[2]
Core capital to Total Assets	4.00%	[2]	4.00%	[2]	4.00%	[2]
Core capital to Total Assets	160,252	[2]	156,942	[2]	159,518	[2]
Core capital to Total Assets	5.00%	[2]	5.00%	[2]	5.00%	[2]
Tier I capital to Risk-based Assets	319,555	[2]	279,947	[2]	263,410	[2]
Tier I capital to Risk-based Assets	14.10%	[2]	12.35%	[2]	11.26%	[2]
Tier I capital to Risk-based Assets	90,685	[2]	0	[2]		[2]
Tier I capital to Risk-based Assets	4.00%	[2]		[2]		[2]
Tier I capital to Risk-based Assets	136,028	[2]	135,403	[2]	139,598	[2]
Tier I capital to Risk-based Assets	6.00%	[2]	6.00%	[2]	6.00%	[2]
Risk-based capital to Risk-based Assets	348,503	[2]	307,178	[2]	291,463	[2]
Risk-based capital to Risk-based Assets	15.37%	[2]	13.61%	[2]	12.53%	[2]
Risk-based capital to Risk-based Assets	181,370	[2]	180,539	[2]	186,131	[2]
Risk-based capital to Risk-based Assets	8.00%	[2]	8.00%	[2]	8.00%	[2]
Risk-based capital to Risk-based Assets	$ 226,713	[2]	$ 225,672	[2]	$ 232,663	[2]
Risk-based capital to Risk-based Assets	10.00%	[2]	10.00%	[2]	10.00%	[2]

[1] The quarter ended March 31, 2012 represented the first period holding company ratios for First Financial were required to be filed with the Federal Reserve Bank included within FR Y-9C, Consolidated Financial Statements for Bank Holding Companies. The capital ratios presented above for the quarter ended September 30, 2012 at the holding company are considered preliminary until the regulatory report is filed with the Federal Reserve Bank.

[2] Capital ratios beginning with the quarter ended March 31, 2012 for First Federal Bank are based on reporting requirements for financial institutions filing FFIEC 041, FDIC Consolidated Reports of Condition and Income (the "Call Report"). Prior period ratios are reported based on superseded regulatory requirements previously issued by the Office of Thrift Supervision.