Convertible Notes (Details) (USD $)	1 Months Ended
	Sep. 30, 2005
Convertible Notes [Abstract]
Issuance date of convertible notes	2005-09
Senior subordinated convertible notes, amount issued	$ 125
Senior subordinated convertible notes issued, interest rate (in Percent)	3.00%
Convertible notes issued, net proceeds	121
Convertible notes issued, proceeds used for share buyback, number of shares	301,000
Convertible notes issued, proceeds used for share buyback, price per share	$ 33.20
Convertible notes issued, proceeds used for share buyback, value	10.0
Convertible notes issued, proceeds used for purchase of call options, net cost	13,000,000
Convertible notes issued, proceeds used for purchase of call options, shares of common stock	3,012,050
Convertible notes issued, proceeds used for purchase of call options, exercise price per share	$ 41.50
Number of common stock a warrant entitles holders to purchase	3,012,050
Exercise price of warrant (in Dollars per Unit)	50.00
Net cash proceeds	$ 98,300,000