Stockholders' Equity (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2013
Stockholders' Equity Note [Abstract]
Increase in stockholders' equity			$ 24,100,000
Net income	7,811,000	24,571,000	12,309,000	54,486,000
Other comprehensive income			1,126,000
Employee stock transactions			10,700,000
Trading days measurement period			160 days
Warrants issued			13,490,236
Warrant, strike price per share	$ 53.8475		$ 53.8475
Authorized repurchase amount					50,000,000
Remaining authorized balance available to repurchase stock	$ 47,300,000		$ 47,300,000
Number of common stock issued			623,000