Stockholders' Equity (Details) (USD $)	1 Months Ended		12 Months Ended
	Sep. 30, 2009	Aug. 31, 2008 VotingRights	Dec. 31, 2011	Dec. 31, 2009	Dec. 31, 2010
Stockholders Equity Additional (Textual) [Abstract]
Initial exercise price of common stock			$ 32.70
Stockholder's Equity (Textual) [Abstract]
Common stock, par value	$ 0.01		$ 0.01		$ 0.01
Portion of shares of series A junior participating preferred stock which right holders are allowed to purchase			0.01
Purchase price per one-hundredth of a share series A junior participating preferred stock which right holders are allowed to purchase			$ 95.00
Number of days for acquiring person, after which rights will be exercisable			10 days
Eligibility for becoming acquiring person			obtaining beneficial ownership of 22% or more of the Company’s outstanding common stock
Minimum ownership percentage in outstanding common stock to become acquiring person			22.00%
Amount offered for all share of common stock under qualified offer			25% higher than the 12-month moving average closing price of the Company’s common stock, and 25% higher than the closing price of the Company’s common stock on the day immediately preceding commencement of the offer
Number of business days under sub condition two			10 days
Percentage higher than 12 month moving average			25.00%
Period of moving average required for calculation purpose			12 months
Number of business days for which qualified offer remains open			106 days
Minimum percentage of company's common stock tendered to offeror			51.00%
Number of business days in which special meeting is held to approve redemption of outstanding rights maximum			105 days
Basis for market value of each right under right's agreement			twice the Right’s then-current exercise price
Dividend payments to preferred stock holders			Quarterly dividend payments of $.01 per one one-hundredth of a share, or an amount equal to the dividend paid on one share of common stock, whichever is greater
Preferred stock liquidation per share amount description			either to receive $1 per one one-hundredth of a share or an amount equal to the payment made on one share of common stock, whichever is greater
Expiration date of rights			Aug. 12, 2012
Redemption price of right prior to distribution date			$ 0.001
Maximum percentage of company's outstanding common stock before which company can extinguish rights			50.00%
Minimum ownership percentage to become acquiring person through amendment			10.00%
Common stock offered and sold	6,000,000
Sale of common stock, price per share	$ 21.80
Issuance of common stock	$ 125,300,000			$ 125,297,000
Increase in additional paid in capital due to convertible notes, purchase options & warrants issued	$ 33,200,000
Number of rights for each outstanding share of common stock		1
Exercise price of rights		$ 95.00
Extinguishment value of rights			One share of common stock
Series A Junior Participating Preferred Stock [Member]
Stockholders Equity Additional (Textual) [Abstract]
Initial exercise price of common stock			$ 95.00