Stockholders' Equity	3 Months Ended
Mar. 31, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity The Company's Board of Directors has approved a stock repurchase program (the "Program") under which the Company may purchase up to an aggregate of $2.1 billion of its common stock over the following 18 month period. The Program was updated most recently on January 23, 2019, the Company's Board of Directors, with an authorized increase in the size of the program by an additional $500 million. With the increase and giving effect to the Company's $1.6 billion of previous repurchases, the Company may repurchase up to $545 million in shares of its common stock at any time prior to February 1, 2020. Any stock repurchases may be made at times and in such amounts as deemed appropriate. The timing and amount of stock repurchases, if any, will depend on a variety of factors including the stock price, market conditions, corporate and regulatory requirements, and any additional constraints related to material inside information the Company may possess. Any repurchases have been and are expected to be funded by a combination of available cash flow from the business, working capital and debt. On December 14, 2018, as part of the Program, the Company entered an accelerated stock repurchase agreement ("2018 ASR Agreement") with a third-party financial institution to repurchase $220 million of its common stock. Pursuant to the 2018 ASR Agreement, the Company delivered $220 million in cash and received 1,057,035 shares based on a stock price of $176.91 on December 14, 2018. The 2018 ASR Agreement was completed on January 29, 2019, at which time the Company received 117,751 additional shares based on a final weighted average per share purchase price during the repurchase period of $187.27. The Company accounted for the ASR Agreement as two separate transactions: (i) as shares of reacquired common stock for the shares delivered to the Company upon effectiveness of each ASR agreement and (ii) as a forward contract indexed to the Company's common stock for the undelivered shares. The initial delivery of shares was included in treasury stock at cost and results in an immediate reduction of the outstanding shares used to calculate the weighted average common shares outstanding for basic and diluted earnings per share. The forward contracts indexed to the Company's own common stock met the criteria for equity classification, and these amounts were initially recorded in additional paid-in capital. Since the beginning of the Program, 9,052,163 shares for an aggregate purchase price of $1.6 billion have been repurchased.

Stockholders' Equity

The Company's Board of Directors has approved a stock repurchase program (the "Program") under which the Company may purchase up to an aggregate of $2.1 billion of its common stock over the following 18 month period. The Program was updated most recently on January 23, 2019, the Company's Board of Directors, with an authorized increase in the size of the program by an additional $500 million. With the increase and giving effect to the Company's $1.6 billion of previous repurchases, the Company may repurchase up to $545 million in shares of its common stock at any time prior to February 1, 2020.

Any stock repurchases may be made at times and in such amounts as deemed appropriate. The timing and amount of stock repurchases, if any, will depend on a variety of factors including the stock price, market conditions, corporate and regulatory requirements, and any additional constraints related to material inside information the Company may possess. Any repurchases have been and are expected to be funded by a combination of available cash flow from the business, working capital and debt.

On December 14, 2018, as part of the Program, the Company entered an accelerated stock repurchase agreement ("2018 ASR Agreement") with a third-party financial institution to repurchase $220 million of its common stock. Pursuant to the 2018 ASR Agreement, the Company delivered $220 million in cash and received 1,057,035 shares based on a stock price of $176.91 on December 14, 2018. The 2018 ASR Agreement was completed on January 29, 2019, at which time the Company received 117,751 additional shares based on a final weighted average per share purchase price during the repurchase period of $187.27.

The Company accounted for the ASR Agreement as two separate transactions: (i) as shares of reacquired common stock for the shares delivered to the Company upon effectiveness of each ASR agreement and (ii) as a forward contract indexed to the Company's common stock for the undelivered shares. The initial delivery of shares was included in treasury stock at cost and results in an immediate reduction of the outstanding shares used to calculate the weighted average common shares outstanding for basic and diluted earnings per share. The forward contracts indexed to the Company's own common stock met the criteria for equity classification, and these amounts were initially recorded in additional paid-in capital.

Since the beginning of the Program, 9,052,163 shares for an aggregate purchase price of $1.6 billion have been repurchased.