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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Options, Issued

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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

Amount of discretionary contributions made by an employer to a defined contribution plan.

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No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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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

Discount rate from fair value on offering date that participants pay for shares.

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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).

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- Definition

Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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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.

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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

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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- Definition

Number of options outstanding, including both vested and non-vested options.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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No definition available.

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- Definition

Percentage of vesting of share-based compensation awards.

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EMPLOYEE BENEFIT PLANS - Other information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee benefits
Number of share options exercisable					1,830,672
Stock Options
Employee benefits
Total remaining compensation cost related to unvested share options				$ 0.0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number					1,830,672
Restricted Stock
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Options, Issued				6,141,613
Total remaining compensation cost related to unvested share options				$ 4.8
Weighted average remaining contractual life				1 year 10 months 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 34.16
Stock based compensation expense				$ 4.3	$ 4.0	$ 3.4
Restricted Stock \| Minimum
Employee benefits
Vesting period				3 years
Restricted Stock \| Maximum
Employee benefits
Vesting period				4 years
Long Term Incentive Plan
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Options, Issued				1,766,550
Total remaining compensation cost related to unvested share options				$ 8.0
Shares available for issuance under plan				7,269,166
Weighted average remaining contractual life				1 year 8 months 12 days
Stock based compensation expense				$ 9.9	8.9	10.0
2017 LTIP
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage				100.00%
FFO as Adjusted Per Share, Value				$ 16.63
Share Price				$ 35.95
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate				23.00%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date				7.50%
Vesting period		3 years
2017 LTIP \| First portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		30.00%
FFO as Adjusted Per Share, Value				$ 16.18
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date				10.00%
Vesting period		1 year
2017 LTIP \| 50% vesting out of first portion of LTI Award
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
2017 LTIP \| Balance 50% vesting out of first portion of LTI Award
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
2017 LTIP \| Second portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		10.00%
2017 LTIP \| Third portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		60.00%
Vesting period		3 years
2017 LTIP \| Relative component
Employee benefits
FFO as Adjusted Per Share, Value				$ 20.54
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date				7.50%
2017 LTIP \| Absolute component
Employee benefits
FFO as Adjusted Per Share, Value				$ 14.71
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date				7.50%
2017 LTIP \| Restricted Stock \| Relative component
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 44.26
2017 LTIP \| Restricted Stock \| Absolute component
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 31.40
2018 LTIP
Employee benefits
FFO as Adjusted Per Share, Value	$ 18.08
Share Price	$ 38.06
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	17.00%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	5.00%
Vesting period	3 years
2018 LTIP \| First portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	30.00%
FFO as Adjusted Per Share, Value	$ 17.13
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	10.00%
Vesting period	1 year
2018 LTIP \| 50% vesting out of first portion of LTI Award
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
2018 LTIP \| Balance 50% vesting out of first portion of LTI Award
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
2018 LTIP \| Second portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	15.00%
2018 LTIP \| Third portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	55.00%
Vesting period	3 years
2018 LTIP \| Relative component
Employee benefits
FFO as Adjusted Per Share, Value	$ 20.12
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	5.00%
2018 LTIP \| Absolute component
Employee benefits
FFO as Adjusted Per Share, Value	$ 19.35
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	5.00%
2018 LTIP \| Restricted Stock \| Relative component
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 42.18
2018 LTIP \| Restricted Stock \| Absolute component
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 40.49
2016 LTIP
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage				100.00%
FFO as Adjusted Per Share, Value				$ 16.64
Share Price				36.97
2016 LTIP \| First portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			33.33%
Vesting period			1 year
2016 LTIP \| 50% vesting out of first portion of LTI Award
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			50.00%
2016 LTIP \| Balance 50% vesting out of first portion of LTI Award
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			50.00%
2016 LTIP \| Second portion of awards
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			66.67%
Vesting period			3 years
2016 LTIP \| Restricted Stock
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 41.22
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate				21.80%
2016 LTIP \| Long Term Incentive Plan
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 19.15
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate				21.80%
2015 LTIP \| Restricted Stock
Employee benefits
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date				10.00%
Long Term Incentive Plan
Employee benefits
Shares reserved for issuance under plan				19,000,000
Profit Sharing Plan
Employee benefits
Aggregate provisions for contributions				$ 1.3	$ 1.3	$ 1.3