Repurchase of Common Stock (Details) (4.50% Notes and/or common stock [Member], USD $) In Thousands, unless otherwise specified	0 Months Ended			9 Months Ended
	Dec. 12, 2008	Oct. 13, 2008	Sep. 30, 2005	Sep. 30, 2013
4.50% Notes and/or common stock [Member]
Equity, Class of Treasury Stock [Line Items]
Interest rate on notes excluded from earnings per share calculation (percent)		4.50%
Stock repurchase program, authorized amount	$ 30,000	$ 30,000	$ 9,864
Stock repurchase program, remaining authorized repurchase amount	$ 1,888			$ 18,304