The number of shares issued cumulatively under the employee stock purchase plan.

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The maximum annual compensation amount to be earned by non-employee directors. Includes grants of share-based compensation awards and any cash fees paid to such non-employee director during the fiscal year.

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- Definition

Closing price of the Company's stock on the last day of the most recent fiscal year end used to compute the aggregate intrinsic value of options outstanding and exercisable or RSUs outstanding and expected to vest as of period end.

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No definition available.

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- Definition

Percentage of an employee's annual target incentive compensation which is eligible to be elected and received in the form of RSUs in accordance with the Company's CICP.

+ References

No definition available.

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- Definition

The total vest date fair value of awards vested during the period.

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No definition available.

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- Definition

Number of options, including both vested and non-vested, and RSUs outstanding as of the balance sheet date.

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No definition available.

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- Definition

The minimum discounted purchase price calculated as a percentage of fair market value of the Company's stock on either the commencement date or completion date of the offerings, whichever is less, at which employees are able to purchase shares under the plan.

+ References

No definition available.

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- Definition

The current discounted purchase price calculated as a percentage of the fair market value of Company's stock the completion date of the offerings at which employees are able to purchase shares under the plan as determined by the board of directors.

+ References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Percentage of vesting of share-based compensation awards.

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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

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No definition available.

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- Definition

Number of share options (or share units) exercised during the current period.

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STOCK-BASED COMPENSATION - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years
Shares available for issuance (shares)	8,300,000
Shares exercised (shares)	1,422,000
Closing price of company stock (dollars per share)	$ 47.83
Vesting one year from the grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Vesting rights percentage	20.00%
Vesting in quarterly installments over the remaining four years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Vesting rights percentage	80.00%
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	10 years
Weighted-average grant date fair value of options granted (dollars per share)	$ 18.03	$ 13.79	$ 8.31
Intrinsic value of stock options exercised	$ 56,800,000	$ 62,600,000	$ 19,900,000
Unrecognized stock-based compensation expense, unvested stock options	$ 21,100,000
Weighted-average period of expense recognition	2 years 4 months
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense, unvested stock options	$ 42,300,000
Weighted-average period of expense recognition	2 years 1 month
Weighted-average grant date fair value of shares granted (dollars per share)	$ 58.52	$ 46.07	$ 25.54
Fair value of shares vested	$ 66,500,000	$ 59,000,000	$ 29,200,000
Corporate Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	100.00%
Percentage of closing price of common stock	85.00%
Corporate Incentive Compensation Plan \| RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation percentage of target incentive compensation eligible to be elected and received by employees	50.00%
2004 Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (shares)			30,000,000
Number of shares subject to outstanding options and awards (shares)	9,600,000
Shares available for issuance (shares)	7,700,000
2004 Long-Term Incentive Plan \| RSUs \| Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual limited compensation			$ 500,000.0
2006 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (shares)				1,000,000
Percentage of fair market value of company stock				85.00%
Purchase price percentage of fair market value				95.00%
Compensation expense recognized	$ 0
Shares issued (shares)	400,000.0
Shares available for issuance (shares)	600,000