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Net number of share options (or share units) granted during the period.

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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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Amount of stock repurchase plan authorized.

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The maximum potential share payout at each balance sheet date.

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Share Capital - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	May 13, 2016	Aug. 06, 2015
Shareholders Equity Disclosure [Line Items]
Stock Repurchased and Retired During Period, Shares	9,700,000	19,700,000
Stock Repurchased and Retired During Period, Value	$ 328.3	$ 683.5
Two Thousand Fifteen Share Repurchase Authorization
Shareholders Equity Disclosure [Line Items]
Stock Repurchase Program, Authorized Amount				$ 1,000.0
Stock Repurchased and Retired During Period, Shares	4,200,000	14,200,000
Stock Repurchased and Retired During Period, Value	$ 144.1	$ 499.3
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 204.1
Two Thousand Sixteen Share Repurchase Authorization [Member]
Shareholders Equity Disclosure [Line Items]
Stock Repurchase Program, Authorized Amount			$ 1,000.0
Stock Repurchased and Retired During Period, Shares	5,500,000	5,500,000
Stock Repurchased and Retired During Period, Value	$ 184.2	$ 184.2
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 815.8	$ 815.8
Stock options
Shareholders Equity Disclosure [Line Items]
Weighted Average Grant Date Fair Value Per Stock Option		$ 5.99
Number of Stock Options Granted During the Period		2,200,000
Restricted Stock [Member]
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period		11,979
Aggregate Grant Date Fair Value of Award		$ 0.4
Restricted stock units
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period		1,100,000
Aggregate Grant Date Fair Value of Award		$ 38.3
Deferred Compensation, Share-based Payments
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period		1,800,000
Aggregate Grant Date Fair Value of Award		$ 61.4
Performance Shares
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period		700,000
Share Based Compensation Arrangement Performance Units Maximum Share Payout Number		1,500,000
Aggregate Grant Date Fair Value of Award		$ 25.6
Minimum
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Minimum \| Performance Shares
Shareholders Equity Disclosure [Line Items]
Performance Units Final Payout Percentage Of Grant Amount		0.00%
Maximum
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
Maximum \| Performance Shares
Shareholders Equity Disclosure [Line Items]
Performance Units Final Payout Percentage Of Grant Amount		200.00%
Three Year Option \| Restricted stock units
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Three Year Option \| Deferred Compensation, Share-based Payments
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Four Year Option \| Restricted stock units
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
Four Year Option \| Deferred Compensation, Share-based Payments
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years