16. Stock repurchase programs

        Under a resolution adopted in November 2011, the Board of Directors authorized the repurchase, at management's discretion, of up to an aggregate of $125 million of our common stock. Under a resolution adopted in June 2014, the Company increased this balance by $150 million. The resolutions also authorized the use of option exercise proceeds for the repurchase of our common stock. During the years ended September 30, 2014, 2013 and 2012, we repurchased 2.7 million, 1.0 million and 0.6 million common shares at a cost of $113.1 million, $32.5 million and $12.8 million, respectively. At September 30, 2014, $135.2 million remained available for future stock repurchases.

        We acquired an additional 0.8 million common shares at a cost of $30.6 million between October 1, 2014 and November 17, 2014.