Treasury Stock	9 Months Ended
Sep. 30, 2018
Equity [Abstract]
TREASURY STOCK	TREASURY STOCK Stock Repurchase Program The Company’s Board of Directors authorized an ongoing stock repurchase program with a total repurchase authority granted to the Company of $9.3 billion, of which $750.0 million was approved in October 2018. The Company may use the approved dollar authority to repurchase stock at any time until the approved amount is exhausted. The objective of the Company’s stock repurchase program is to improve stockholders’ returns. At September 30, 2018, $397.9 million was available to repurchase common stock pursuant to the stock repurchase program. All shares repurchased are recorded as treasury stock. A portion of the funds used to repurchase stock over the course of the program was provided by net proceeds from the Convertible Notes and 2027 Notes offerings, as well as proceeds from employee stock awards and the related tax benefit. The Company is authorized to make purchases of its common stock using general corporate funds through open market purchases, pursuant to a Rule 10b5-1 plan or in privately negotiated transactions. In November 2017, the Company purchased $750.0 million of shares of its common stock through the ASR Agreement with the ASR Counterparty. The Company paid $750.0 million to the ASR Counterparty under the ASR agreement and received approximately 7.1 million shares of its common stock from the ASR Counterparty, which represented 80 percent of the value of the shares to be repurchased pursuant to the ASR Agreement. The total number of shares of common stock that the Company repurchased under the ASR Agreement was based on the average of the daily volume-weighted average prices of its common stock during the term of the ASR Agreement, less a discount. Final settlement of the ASR agreement was completed in January 2018 and the Company received delivery of an additional 1.4 million shares of its common stock. In February 2018, the Company entered into an ASR transaction with Goldman Sachs & Co. LLC (“Dealer”) to pay an aggregate of $750.0 million in exchange for the delivery of approximately 6.5 million shares of its common stock based on current market prices. The purchase price per share under the ASR was based on the volume-weighted average price of the Company's common stock during the term of the ASR, less a discount. The ASR was entered into pursuant to the Company's existing share repurchase program. Final settlement of the ASR agreement was completed in April 2018 and the Company received delivery of an additional 1.6 million additional shares of its common stock. During the three months ended September 30, 2018, the Company expended approximately $116.2 million on open market purchases under the stock repurchase program, repurchasing 1.0 million shares of common stock at an average price of $111.11. During the nine months ended September 30, 2018, the Company expended approximately $131.2 million on open market purchases under the stock repurchase program, repurchasing 1.2 million shares of common stock at an average price of $110.60. During the three months ended September 30, 2017, the Company expended $75.0 million on open market purchases under the stock repurchase program, repurchasing 1.0 million shares of common stock at an average price of $76.11. During the nine months ended September 30, 2017, the Company expended $575.0 million on open market purchases under the stock repurchase program, repurchasing 7.4 million shares of common stock at an average price of $77.86. Shares for Tax Withholding During the three and nine months ended September 30, 2018, the Company withheld 32,813 shares and 0.6 million shares, respectively, from equity awards that vested, totaling $3.7 million and $53.6 million, respectively, to satisfy minimum tax withholding obligations that arose on the vesting of such equity awards. During the three and nine months ended September 30, 2017, the Company withheld 0.1 million shares and 0.9 million shares, respectively, from equity awards that vested, totaling $10.6 million and $71.2 million, respectively, to satisfy minimum tax withholding obligations that arose on the vesting of such equity awards. These shares are reflected as treasury stock in the Company’s condensed consolidated balance sheets and the related cash outlays do not reduce the Company’s total stock repurchase authority.

TREASURY STOCK

Stock Repurchase Program

The Company’s Board of Directors authorized an ongoing stock repurchase program with a total repurchase authority granted to the Company of $9.3 billion, of which $750.0 million was approved in October 2018. The Company may use the approved dollar authority to repurchase stock at any time until the approved amount is exhausted. The objective of the Company’s stock repurchase program is to improve stockholders’ returns. At September 30, 2018, $397.9 million was available to repurchase common stock pursuant to the stock repurchase program. All shares repurchased are recorded as treasury stock. A portion of the funds used to repurchase stock over the course of the program was provided by net proceeds from the Convertible Notes and 2027 Notes offerings, as well as proceeds from employee stock awards and the related tax benefit. The Company is authorized to make purchases of its common stock using general corporate funds through open market purchases, pursuant to a Rule 10b5-1 plan or in privately negotiated transactions.

In November 2017, the Company purchased $750.0 million of shares of its common stock through the ASR Agreement with the ASR Counterparty. The Company paid $750.0 million to the ASR Counterparty under the ASR agreement and received approximately 7.1 million shares of its common stock from the ASR Counterparty, which represented 80 percent of the value of the shares to be repurchased pursuant to the ASR Agreement. The total number of shares of common stock that the Company repurchased under the ASR Agreement was based on the average of the daily volume-weighted average prices of its common stock during the term of the ASR Agreement, less a discount. Final settlement of the ASR agreement was completed in January 2018 and the Company received delivery of an additional 1.4 million shares of its common stock.

In February 2018, the Company entered into an ASR transaction with Goldman Sachs & Co. LLC (“Dealer”) to pay an aggregate of $750.0 million in exchange for the delivery of approximately 6.5 million shares of its common stock based on current market prices. The purchase price per share under the ASR was based on the volume-weighted average price of the Company's common stock during the term of the ASR, less a discount. The ASR was entered into pursuant to the Company's existing share repurchase program. Final settlement of the ASR agreement was completed in April 2018 and the Company received delivery of an additional 1.6 million additional shares of its common stock.

During the three months ended September 30, 2018, the Company expended approximately $116.2 million on open market purchases under the stock repurchase program, repurchasing 1.0 million shares of common stock at an average price of $111.11. During the nine months ended September 30, 2018, the Company expended approximately $131.2 million on open market purchases under the stock repurchase program, repurchasing 1.2 million shares of common stock at an average price of $110.60.

During the three months ended September 30, 2017, the Company expended $75.0 million on open market purchases under the stock repurchase program, repurchasing 1.0 million shares of common stock at an average price of $76.11. During the nine months ended September 30, 2017, the Company expended $575.0 million on open market purchases under the stock repurchase program, repurchasing 7.4 million shares of common stock at an average price of $77.86.

Shares for Tax Withholding

During the three and nine months ended September 30, 2018, the Company withheld 32,813 shares and 0.6 million shares, respectively, from equity awards that vested, totaling $3.7 million and $53.6 million, respectively, to satisfy minimum tax withholding obligations that arose on the vesting of such equity awards. During the three and nine months ended September 30, 2017, the Company withheld 0.1 million shares and 0.9 million shares, respectively, from equity awards that vested, totaling $10.6 million and $71.2 million, respectively, to satisfy minimum tax withholding obligations that arose on the vesting of such equity awards. These shares are reflected as treasury stock in the Company’s condensed consolidated balance sheets and the related cash outlays do not reduce the Company’s total stock repurchase authority.