Capital Stock	6 Months Ended
Jun. 30, 2017
Equity [Abstract]
Capital Stock	Capital Stock Pursuant to our tax benefits preservation plan (Plan) adopted January 5, 2017, as amended on April 13, 2017 and June 29, 2017, each share of common stock outstanding is coupled with one preferred stock purchase right (Right). Each Right entitles our stockholders to purchase, under certain conditions, one one-thousandth of a share (Unit) of newly issued Series B Junior Participating Preferred Stock at a purchase price of $50 per Unit, subject to adjustment. Rights will be exercisable only if someone becomes a five-percent stockholder after adoption of the Plan without meeting certain customary exceptions. Stockholders owning five percent or more of our outstanding stock at the time of adoption of the Plan are grandfathered and will cause Rights to be distributed and become exercisable only if they acquire an additional one percent of our outstanding shares. Our board of directors has the discretion to exempt certain transactions and persons from the coverage of the Plan, and the Plan has been amended to exempt the D.R. Horton Merger Agreement from the coverage of the Plan. The Plan will terminate immediately prior to the effective time of the D. R. Horton Merger Agreement and, in the event the D.R. Horton Merger Agreement is not consummated, the Rights will expire on January 5, 2020.

Capital Stock

Pursuant to our tax benefits preservation plan (Plan) adopted January 5, 2017, as amended on April 13, 2017 and June 29, 2017, each share of common stock outstanding is coupled with one preferred stock purchase right (Right). Each Right entitles our stockholders to purchase, under certain conditions, one one-thousandth of a share (Unit) of newly issued Series B Junior Participating Preferred Stock at a purchase price of $50 per Unit, subject to adjustment. Rights will be exercisable only if someone becomes a five-percent stockholder after adoption of the Plan without meeting certain customary exceptions. Stockholders owning five percent or more of our outstanding stock at the time of adoption of the Plan are grandfathered and will cause Rights to be distributed and become exercisable only if they acquire an additional one percent of our outstanding shares. Our board of directors has the discretion to exempt certain transactions and persons from the coverage of the Plan, and the Plan has been amended to exempt the D.R. Horton Merger Agreement from the coverage of the Plan. The Plan will terminate immediately prior to the effective time of the D. R. Horton Merger Agreement and, in the event the D.R. Horton Merger Agreement is not consummated, the Rights will expire on January 5, 2020.