Stockholder Protection Rights Plan	12 Months Ended
Dec. 31, 2011
Stockholder Protection Rights Plan [Abstract]
Stockholder Protection Rights Plan	16. Stockholder Protection Rights Plan Effective April 16, 1997, the Company's board of directors declared a distribution of one right (“Rights”) for each outstanding share of the Company's common stock to stockholders of record at the close of business on May 15, 1997 and for each share of common stock issued by the Company thereafter and prior to a Flip-in Date (as defined below). Each Right entitles the registered holder to purchase from the Company one-ten thousandth (1/10,000th) of a share of Series A Junior Participating Preferred Stock, at an exercise price of $30. The Rights are generally not exercisable until 10 business days after an announcement by the Company that a person or group of affiliated persons (an “Acquiring Person”) has acquired beneficial ownership of 15% or more of the Company's then outstanding shares of common stock (a “Flip-in Date”). In the event the Rights become exercisable as a result of the acquisition of shares, each Right will enable the owner, other than the Acquiring Person, to purchase at the Right's then-current exercise price a number of shares of common stock with a market value equal to twice the exercise price. In addition, unless the Acquiring Person owns more than 50% of the outstanding shares of common stock, the Board of Directors may elect to exchange all outstanding Rights (other than those owned by such Acquiring Person) at an exchange ratio of one share of common stock per Right. All Rights that are owned by any person on or after the date such person becomes an Acquiring Person will be null and void. The Rights have been distributed to protect the Company's stockholders from coercive or abusive takeover tactics and to give the Board of Directors more negotiating leverage in dealing with prospective acquirers. In April 2007, the Company extended the stockholder rights plan through April 2017.

16. Stockholder Protection Rights Plan

Effective April 16, 1997, the Company's board of directors declared a distribution of one right (“Rights”) for each outstanding share of the Company's common stock to stockholders of record at the close of business on May 15, 1997 and for each share of common stock issued by the Company thereafter and prior to a Flip-in Date (as defined below). Each Right entitles the registered holder to purchase from the Company one-ten thousandth (1/10,000th) of a share of Series A Junior Participating Preferred Stock, at an exercise price of $30. The Rights are generally not exercisable until 10 business days after an announcement by the Company that a person or group of affiliated persons (an “Acquiring Person”) has acquired beneficial ownership of 15% or more of the Company's then outstanding shares of common stock (a “Flip-in Date”).

In the event the Rights become exercisable as a result of the acquisition of shares, each Right will enable the owner, other than the Acquiring Person, to purchase at the Right's then-current exercise price a number of shares of common stock with a market value equal to twice the exercise price. In addition, unless the Acquiring Person owns more than 50% of the outstanding shares of common stock, the Board of Directors may elect to exchange all outstanding Rights (other than those owned by such Acquiring Person) at an exchange ratio of one share of common stock per Right. All Rights that are owned by any person on or after the date such person becomes an Acquiring Person will be null and void.

The Rights have been distributed to protect the Company's stockholders from coercive or abusive takeover tactics and to give the Board of Directors more negotiating leverage in dealing with prospective acquirers. In April 2007, the Company extended the stockholder rights plan through April 2017.