16. Stock repurchase programs

        All common stock amounts have been adjusted for the two-for-one stock split in June 2013.

        Under resolutions adopted in July 2008 and September 2010, the Board of Directors authorized the repurchase, at management's discretion, of up to an aggregate of $175.0 million of the Company's common stock. In November 2011, this plan was replaced with a new program which authorized up to $125.0 million of repurchases. The Board has also authorized the use of option exercise proceeds for the repurchase of the Company's common stock. During the years ended September 30, 2013, 2012 and 2011, the Company repurchased 974,498, 612,000 and 3,194,916 common shares at a cost of $32.5 million, $12.8 million and $57.5 million, respectively. At September 30, 2013, $97.1 million remained available for future stock repurchases.