Stock Repurchases	6 Months Ended
Jun. 30, 2012
Stock Repurchases [Abstract]
Stock Repurchases	11. STOCK REPURCHASES On August 5, 1999, our board of directors approved a stock repurchase program which authorizes us to repurchase common shares in the open market or in privately negotiated transactions at price levels we deem attractive. On March 26, 2012, the board of directors authorized the repurchase of up to one million shares of our common stock in addition to the board’s prior authorizations. As of June 30, 2012, we had authorization to repurchase 976,129 shares of our common stock. During the first two quarters of 2012, we repurchased 285,402 shares of our common stock in the open market at a cost of $27.0 million. During the second quarter of 2012, we commenced a tender offer to repurchase 1.0 million shares of our common stock at a price of $84.45 per share. Upon expiration of the tender offer during the second quarter of 2012, we repurchased 1.0 million common shares at a cost of $84.5 million. As of June 30, 2012, accounts payable and accrued liabilities within our consolidated balance sheet included a payable of $84.5 million related to the settlement of this repurchase transaction. The settlement during the third quarter of 2012 was financed by borrowing under our revolving secured line of credit facility. During the first quarter of 2011, we commenced a tender offer to repurchase 1.9 million shares of our common stock at a price of $65.625 per share. Upon expiration of the tender offer during the first quarter of 2011, we repurchased 1.9 million common shares at a cost of $125.0 million. We financed the repurchase of our common stock in the tender offer using the proceeds from the issuance of $100.0 million of Senior Notes and by borrowing under our revolving secured line of credit facility.

On August 5, 1999, our board of directors approved a stock repurchase program which authorizes us to repurchase common shares in the open market or in privately negotiated transactions at price levels we deem attractive. On March 26, 2012, the board of directors authorized the repurchase of up to one million shares of our common stock in addition to the board’s prior authorizations. As of June 30, 2012, we had authorization to repurchase 976,129 shares of our common stock.

During the first two quarters of 2012, we repurchased 285,402 shares of our common stock in the open market at a cost of $27.0 million.

During the second quarter of 2012, we commenced a tender offer to repurchase 1.0 million shares of our common stock at a price of $84.45 per share. Upon expiration of the tender offer during the second quarter of 2012, we repurchased 1.0 million common shares at a cost of $84.5 million. As of June 30, 2012, accounts payable and accrued liabilities within our consolidated balance sheet included a payable of $84.5 million related to the settlement of this repurchase transaction. The settlement during the third quarter of 2012 was financed by borrowing under our revolving secured line of credit facility.

During the first quarter of 2011, we commenced a tender offer to repurchase 1.9 million shares of our common stock at a price of $65.625 per share. Upon expiration of the tender offer during the first quarter of 2011, we repurchased 1.9 million common shares at a cost of $125.0 million. We financed the repurchase of our common stock in the tender offer using the proceeds from the issuance of $100.0 million of Senior Notes and by borrowing under our revolving secured line of credit facility.