Equity Securities and Stock-Based Compensation (Details) (USD $) Share data in Millions, unless otherwise specified	1 Months Ended	3 Months Ended			6 Months Ended		3 Months Ended
	Feb. 29, 2012	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013 2010 Incentive Compensation Plan
Equity Securities and Stock-Based Compensation
Common stock, shares issued				11.5
Gross proceeds from issuance of common stock				$ 83,400,000
Offering costs				5,400,000
Net proceeds from issuance of common stock				78,000,000	0	77,957,000
Amount available for future offerings of securities	210,000,000			126,600,000
Treasury stock and related deferred compensation obligation at fair value		900,000			900,000
Amount that the fair values of treasury stock and related deferred compensation obligation exceed the carrying values at cost		300,000			300,000
Stock-based compensation		500,000	400,000		1,016,000	821,000
Total compensation cost related to unvested awards not yet recognized		$ 3,300,000			$ 3,300,000
Equity Securities and Stock-based Compensation
Board approved share-based award grants to officers, employees, and directors (in shares)							0.5
Awards granted vesting period							3 years
Period of average stock price hurdles that precluded vesting							60 days