Employee Benefit Plans (Details 12) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 315.0		$ 302.8
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5.8		8.2
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	309.2		294.6
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5.8		8.2
Cash and Cash Equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5.8		8.2
Cash and Cash Equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Cash and Cash Equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Commingled Pools / Collective Trusts [Member] | U.S. equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	78.0		100.1
Commingled Pools / Collective Trusts [Member] | U.S. equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Commingled Pools / Collective Trusts [Member] | U.S. equity [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	78.0		100.1
Commingled Pools / Collective Trusts [Member] | U.S. equity [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Commingled Pools / Collective Trusts [Member] | International equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	47.3	[1]	70.8	[1]
Commingled Pools / Collective Trusts [Member] | International equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Commingled Pools / Collective Trusts [Member] | International equity [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	47.3	[1]	70.8	[1]
Commingled Pools / Collective Trusts [Member] | International equity [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Commingled Pools / Collective Trusts [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	145.4	[2]	89.4	[2]
Commingled Pools / Collective Trusts [Member] | Fixed income [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Commingled Pools / Collective Trusts [Member] | Fixed income [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	145.4	[2]	89.4	[2]
Commingled Pools / Collective Trusts [Member] | Fixed income [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Trust for Benefit of Employees [Member] | International equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	4.7	[3]	10.8	[3]
Trust for Benefit of Employees [Member] | International equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Trust for Benefit of Employees [Member] | International equity [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	4.7	[3]	10.8	[3]
Trust for Benefit of Employees [Member] | International equity [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Trust for Benefit of Employees [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	14.2	[3]	7.2	[3]
Trust for Benefit of Employees [Member] | Fixed income [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Trust for Benefit of Employees [Member] | Fixed income [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	14.2	[3]	7.2	[3]
Trust for Benefit of Employees [Member] | Fixed income [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Pension Fund [Member] | International equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	11.4	[4]	9.4	[4]
Pension Fund [Member] | International equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[4]	0	[4]
Pension Fund [Member] | International equity [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	11.4	[4]	9.4	[4]
Pension Fund [Member] | International equity [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[4]	0	[4]
Pension Fund [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	8.2	[5]	6.9	[5]
Pension Fund [Member] | Fixed income [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[5]	0	[5]
Pension Fund [Member] | Fixed income [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	8.2	[5]	6.9	[5]
Pension Fund [Member] | Fixed income [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 0	[5]	$ 0	[5]

[1] This category includes investments primarily in international equity securities that include large, mid and small capitalization companies in large developed markets as well as emerging markets equities.

[2] This category includes investments in U.S. investment grade and high yield fixed income securities, international fixed income securities and emerging markets fixed income securities.

[3] The investment objectives of the fund are to provide long-term capital growth and income by investing primarily in a well-diversified, balanced portfolio of Canadian common stocks, bonds and money market securities. The fund also holds a portion of its assets in international equities.

[4] This category includes investments in international equity securities and aims to provide returns consistent with the markets in which it invests and provide broad exposure to countries around the world.

[5] This category includes investments in U.K. government index-linked securities (index-linked gilts) that have maturity periods of 5 years or longer and investment grade corporate bonds denominated in sterling.