Timberland Bancorp, Inc. and Subsidiary Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Statement of Financial Position [Abstract]
Mortgage-backed securities and other investments held to maturity-fair value	$ 3,639	$ 3,632
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock shares authorized	1,000,000	1,000,000
Preferred stock shares issued	12,065	16,641
Preferred stock shares outstanding	12,065	16,641
Preferred stock per share liquidation value (in dollars per share)	$ 1,000	$ 1,000
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock shares authorized	50,000,000	50,000,000
Common stock shares issued	7,045,036	7,045,036
Common stock shares outstanding	7,045,036	7,045,036