Employee Retirement Plans (Details Textual) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated employer contributions in current fiscal year	$ 72
Canada [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution by employer	15
Other Domestic and Foreign [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution by employer	4
Subsequent Event [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution by employer	$ 50