SHAREHOLDERS’ EQUITY	12 Months Ended
Dec. 31, 2017
Stockholders' Equity Note [Abstract]
SHAREHOLDERS’ EQUITY	SHAREHOLDERS’ EQUITY We make repurchases of our common stock mainly through the use of open market purchases and, at times, through accelerated share repurchase programs ("ASR's"). As of December 31, 2017, we were authorized to repurchase up to $264.9 million of our common stock. On February 6, 2018, the board increased its authorization to repurchase shares to $600 million. Year Ended December 31, 2017 During the year ended December 31, 2017, through open market repurchase plans, we repurchased and retired 376,309 shares of our common stock at a cost of $34.8 million, or an average cost of $92.51 per share, including commissions. 2016 Fiscal Transition Period During the 2016 fiscal transition period, through open market repurchase plans, we repurchased and retired 2.5 million shares of our common stock at a cost of $178.2 million, or an average cost of $70.77 per share, including commissions. Year Ended May 31, 2016 On April 25, 2016, we entered into an ASR with a financial institution to repurchase an aggregate of $50 million of our common stock. In exchange for an up-front payment of $50 million, the financial institution committed to deliver a number of shares during the ASR's purchase period, which ended on June 23, 2016. On April 26, 2016, 545,777 shares were initially delivered to us. At May 31, 2016, we accounted for the variable component of remaining shares to be delivered under the ASR as a forward contract indexed to our common stock which met all of the applicable criteria for equity classification. On June 23, 2016, an additional 127,435 shares were delivered to us. The total number of shares delivered under this ASR was 673,212 shares at an average price of $74.27 per share. In addition to shares repurchased under the ASR during the year ended May 31, 2016, we repurchased and retired 1.5 million shares of our common stock at a cost of $85.9 million, or an average cost of $58.12 per share, including commissions, through open market repurchase plans. Year Ended May 31, 2015 On April 10, 2015, we entered into an ASR with a financial institution to repurchase an aggregate of $100 million of our common stock. In exchange for an up-front payment of $100 million, we repurchased 1,955,730 shares at an average price of $51.13 per share. In addition to shares repurchased under the ASR during the year ended May 31, 2015, we repurchased and retired 7.0 million shares of our common stock at a cost of $269.0 million, or an average cost of $38.19 per share, including commissions, through open market repurchase plans.

SHAREHOLDERS’ EQUITY

We make repurchases of our common stock mainly through the use of open market purchases and, at times, through accelerated share repurchase programs ("ASR's"). As of December 31, 2017, we were authorized to repurchase up to $264.9 million of our common stock. On February 6, 2018, the board increased its authorization to repurchase shares to $600 million.

Year Ended December 31, 2017

During the year ended December 31, 2017, through open market repurchase plans, we repurchased and retired 376,309 shares of our common stock at a cost of $34.8 million, or an average cost of $92.51 per share, including commissions.

2016 Fiscal Transition Period

During the 2016 fiscal transition period, through open market repurchase plans, we repurchased and retired 2.5 million shares of our common stock at a cost of $178.2 million, or an average cost of $70.77 per share, including commissions.

Year Ended May 31, 2016

On April 25, 2016, we entered into an ASR with a financial institution to repurchase an aggregate of $50 million of our common stock. In exchange for an up-front payment of $50 million, the financial institution committed to deliver a number of shares during the ASR's purchase period, which ended on June 23, 2016. On April 26, 2016, 545,777 shares were initially delivered to us. At May 31, 2016, we accounted for the variable component of remaining shares to be delivered under the ASR as a forward contract indexed to our common stock which met all of the applicable criteria for equity classification. On June 23, 2016, an additional 127,435 shares were delivered to us. The total number of shares delivered under this ASR was 673,212 shares at an average price of $74.27 per share.

In addition to shares repurchased under the ASR during the year ended May 31, 2016, we repurchased and retired 1.5 million shares of our common stock at a cost of $85.9 million, or an average cost of $58.12 per share, including commissions, through open market repurchase plans.

Year Ended May 31, 2015

On April 10, 2015, we entered into an ASR with a financial institution to repurchase an aggregate of $100 million of our common stock. In exchange for an up-front payment of $100 million, we repurchased 1,955,730 shares at an average price of $51.13 per share. In addition to shares repurchased under the ASR during the year ended May 31, 2015, we repurchased and retired 7.0 million shares of our common stock at a cost of $269.0 million, or an average cost of $38.19 per share, including commissions, through open market repurchase plans.