Pension plans 4 (Details) (USD $) | 12 Months Ended |
In Millions, unless otherwise specified | Dec. 31, 2013 | Dec. 31, 2012 |
Corporate debt securities [Member] | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the beginning of the year | $0 | $2.70 |
Actual return on plan assets | 0 | -0.1 |
Purchases, sales and settlments, net | 0 | -2.5 |
Transfer into (out of) Level 3 | ' | -0.1 |
Foreign currency exchange rates | 0 | 0 |
Fair value of plan assets at the end of the year | 0 | 0 |
General insurance account [Member] | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the beginning of the year | 19 | 19.1 |
Actual return on plan assets | 1 | 0.8 |
Purchases, sales and settlments, net | -3.2 | -1.2 |
Transfer into (out of) Level 3 | ' | 0 |
Foreign currency exchange rates | 0.8 | 0.3 |
Fair value of plan assets at the end of the year | 17.6 | 19 |
U.S. Pension Plans [Member] | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the beginning of the year | 555.3 | 481.4 |
Actual return on plan assets | 65.2 | 68.6 |
Foreign currency exchange rates | 0 | 0 |
Fair value of plan assets at the end of the year | 627.2 | 555.3 |
U.S. Pension Plans [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 213 | 293.6 |
U.S. Pension Plans [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 414.2 | 261.6 |
U.S. Pension Plans [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | Cash and cash equivalents [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 5.9 | 4 |
U.S. Pension Plans [Member] | Cash and cash equivalents [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 9.8 | 10.4 |
U.S. Pension Plans [Member] | Cash and cash equivalents [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | Corporate debt securities [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | Corporate debt securities [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 199.2 | 123.1 |
U.S. Pension Plans [Member] | Corporate debt securities [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | U.S. government debt securities [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 2.7 | 2.2 |
U.S. Pension Plans [Member] | U.S. government debt securities [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | U.S. government debt securities [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | State and municipal debt securities [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | State and municipal debt securities [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 45.6 | 19.1 |
U.S. Pension Plans [Member] | State and municipal debt securities [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | Corporate common stock [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 194.2 | 265 |
U.S. Pension Plans [Member] | Corporate common stock [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 17.5 | 19.7 |
U.S. Pension Plans [Member] | Corporate common stock [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | Registered investment company funds [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 10.2 | 22.4 |
U.S. Pension Plans [Member] | Registered investment company funds [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 133.3 | 74.5 |
U.S. Pension Plans [Member] | Registered investment company funds [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | Common trust funds [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | Common trust funds [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 8.8 | 14.8 |
U.S. Pension Plans [Member] | Common trust funds [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | General insurance account [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | General insurance account [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
U.S. Pension Plans [Member] | General insurance account [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the beginning of the year | 63.3 | 58.7 |
Actual return on plan assets | 5.5 | 4.3 |
Foreign currency exchange rates | 1.5 | 2.1 |
Fair value of plan assets at the end of the year | 67.2 | 63.3 |
Non-U.S. Pension Plans [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 44.8 | 39.9 |
Non-U.S. Pension Plans [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 4.8 | 4.4 |
Non-U.S. Pension Plans [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 17.6 | 19 |
Non-U.S. Pension Plans [Member] | Cash and cash equivalents [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Cash and cash equivalents [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Cash and cash equivalents [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Corporate debt securities [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Corporate debt securities [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Corporate debt securities [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | U.S. government debt securities [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | U.S. government debt securities [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | U.S. government debt securities [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | State and municipal debt securities [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | State and municipal debt securities [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | State and municipal debt securities [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Corporate common stock [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Corporate common stock [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Corporate common stock [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Registered investment company funds [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 44.8 | 39.9 |
Non-U.S. Pension Plans [Member] | Registered investment company funds [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Registered investment company funds [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Common trust funds [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | Common trust funds [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 4.8 | 4.4 |
Non-U.S. Pension Plans [Member] | Common trust funds [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | General insurance account [Member] | (Level 1) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | General insurance account [Member] | (Level 2) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | 0 | 0 |
Non-U.S. Pension Plans [Member] | General insurance account [Member] | (Level 3) | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' |
Fair value of plan assets at the end of the year | $17.60 | $19 |