Investment in Limited Partnerships (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Investment in limited partnerships	$ 2,603	$ 3,113
Pedcor Investments 1997-XXVIII
Schedule of Equity Method Investments [Line Items]
Investment in limited partnerships	1,132	1,415
Pedcor Investments 1987-XXXI
Schedule of Equity Method Investments [Line Items]
Investment in limited partnerships	125	188
Pedcor Investments 2000-XLI
Schedule of Equity Method Investments [Line Items]
Investment in limited partnerships	495	577
Pedcor Investments 2001-LI
Schedule of Equity Method Investments [Line Items]
Investment in limited partnerships	130	152
Pedcor Investments 2008-CIII
Schedule of Equity Method Investments [Line Items]
Investment in limited partnerships	$ 721	$ 781