Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Supplemental Cash Flow Information [Line Items]

Supplemental Cash Flow Information [Table Text Block]

Supplemental cash flow information is shown in the table below:

	Year Ended December 31,
	2016			2015			2014
Supplemental Disclosures	(in millions)
Cash paid for interest, net of capitalized interest	$	139.1		$	139.4		$	163.2
Cash paid (refund received) for income taxes, net	$	(123.5	)	$	487.8		$	0.3
Non-cash investing activities
Change in capital expenditure accrual balance	$	(32.8	)	$	(129.2	)	$	8.4

Property, Plant and Equipment [Table Text Block]

Buildings	10 to 30 years
Leasehold improvements	3 to 10 years
Service, transportation and field service equipment	3 to 7 years
Furniture and office equipment	3 to 7 years

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	December 31,
	2016	2015	2014
	(in millions)
Weighted-average basic common shares outstanding	221.7	176.6	179.8
Potential number of shares issuable upon exercise of in-the-money stock options under the Long-Term Stock Incentive Plan	—	—	—
Average diluted common shares outstanding	221.7	176.6	179.8