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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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Gross number of share options (or share units) granted during the period.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Capital Stock and Equity Awards - Equity Incentive Plans (Details) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	May 02, 2017
Non-qualified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options granted	205,244	706,203
Exercise price (in dollars per share)	$ 42.24	$ 32.07
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted	119,312	60,291
Fair value at date of grant (in dollars per share)	$ 42.19	$ 32.03
2014 LTIP \| Non-qualified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for issuance	4,171,150
Number of shares available for grant	1,865,141
Vesting period (in years)	3 years
2014 LTIP \| RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
2014 LTIP \| RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years
2014 Director Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for issuance	50,000
Number of shares available for grant	32,994
2014 Director Plan \| RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
2014 Director Plan \| RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years
Common stock \| Amendment to the 2014 LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for issuance			1,000,000
Number of shares available for grant			500,000