Stockholder Rights Plan	12 Months Ended
Dec. 31, 2016
Stockholder Rights Plan [Abstract]
StockholderRightsPlan [Text Block]	Stockholder Rights Plan In July 1997, our Board of Directors adopted a Stockholder Rights Plan. This plan expired in 2007 and in July 2007, our Board of Directors adopted an Amended and Restated Rights Agreement. We distributed a Preferred Share Purchase Right (a “Right”) for each share of our Common Stock outstanding. The Rights generally will not be exercisable until a person or group has acquired 15% or more of our Common Stock in a transaction that is not approved in advance by the Board of Directors or ten days after the commencement of a tender offer, which could result in a person or group owning 15% or more of our Common Stock. On exercise, each Right entitles the holder to buy one share of Common Stock at an exercise price of $225. In the event a third party or group were to acquire 15% or more of our outstanding Common Stock without the prior approval of the Board of Directors, each Right will entitle the holder, other than the acquirer, to buy Common Stock with a market value of twice the exercise price, for the Right’s then current exercise price. In addition, if we were to be acquired in a merger after such an acquisition, shareholders with unexercised Rights could purchase common stock of the acquirer with a value of twice the exercise price of the Rights. Our Board of Directors may redeem the Rights for a nominal amount at any time prior to the tenth business day following an event that causes the Rights to become exercisable. The Rights will expire unless previously redeemed or exercised on August 8, 2017.

Stockholder Rights Plan

In July 1997, our Board of Directors adopted a Stockholder Rights Plan. This plan expired in 2007 and in July 2007, our Board of Directors adopted an Amended and Restated Rights Agreement. We distributed a Preferred Share Purchase Right (a “Right”) for each share of our Common Stock outstanding. The Rights generally will not be exercisable until a person or group has acquired 15% or more of our Common Stock in a transaction that is not approved in advance by the Board of Directors or ten days after the commencement of a tender offer, which could result in a person or group owning 15% or more of our Common Stock.

On exercise, each Right entitles the holder to buy one share of Common Stock at an exercise price of $225. In the event a third party or group were to acquire 15% or more of our outstanding Common Stock without the prior approval of the Board of Directors, each Right will entitle the holder, other than the acquirer, to buy Common Stock with a market value of twice the exercise price, for the Right’s then current exercise price. In addition, if we were to be acquired in a merger after such an acquisition, shareholders with unexercised Rights could purchase common stock of the acquirer with a value of twice the exercise price of the Rights.

Our Board of Directors may redeem the Rights for a nominal amount at any time prior to the tenth business day following an event that causes the Rights to become exercisable. The Rights will expire unless previously redeemed or exercised on August 8, 2017.