Financial Statements for Guarantors of the Senior Notes - Statement of Operations and Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Income Statements, Captions [Line Items]
Revenues	$ 735.0	$ 606.9	$ 634.0	$ 533.2	$ 615.4	$ 655.7	$ 595.7	$ 530.6	$ 2,509.1	$ 2,397.4	$ 3,089.8
Cost of revenues	590.5	466.5	481.9	399.9	455.8	480.8	450.8	387.8	1,938.8	1,775.2	2,312.0
Selling, engineering, and administrative expenses	72.0	75.6	75.6	73.4	88.5	85.8	85.8	79.2	296.6	339.3	313.9
Gains on dispositions on property	17.3	10.4	11.5	2.2	44.4	16.0	24.0	1.0	41.4	85.4	15.0
Cost of revenues and operating costs									2,194.0	2,029.1	2,610.9
Operating Profit (Loss)	89.8	75.2	88.0	62.1	115.5	105.1	83.1	64.6	315.1	368.3	478.9
Other (income) expense									163.5	172.9	168.9
Equity in earnings of subsidiaries, net of taxes									0.0	0.0	0.0
Income (loss) before income taxes	45.7	35.2	49.8	20.9	74.0	60.2	38.8	22.4	151.6	195.4	310.0
Provision (benefit) for income taxes	17.7	6.7	12.5	5.7	(457.9)	23.4	16.7	3.0	42.6	(414.8)	106.8
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	28.0	28.5	37.3	15.2	531.9	36.8	22.1	19.4	109.0	610.2	203.2
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(0.3)	(0.2)	28.2	26.4	8.1	31.1	31.9	32.3	54.1	103.4	161.5
Net income from continuing operations	27.7	28.3	65.5	41.6	540.0	67.9	54.0	51.7	163.1	713.6	364.7
Net income attributable to noncontrolling interest									3.8	11.1	21.1
Net income (loss) attributable to controlling interest	$ 27.3	$ 27.7	$ 64.1	$ 40.2	$ 538.5	$ 66.9	$ 51.1	$ 46.0	159.3	702.5	343.6
Other comprehensive income									(13.2)	11.3	5.0
Comprehensive income									149.9	724.9	369.7
Comprehensive income attributable to noncontrolling interest									5.2	13.7	24.2
Comprehensive income attributable to controlling interest									144.7	711.2	345.5
Reportable legal entities | Parent
Condensed Income Statements, Captions [Line Items]
Revenues									0.0	0.0	0.0
Cost of revenues									2.0	3.0	(1.4)
Selling, engineering, and administrative expenses									141.7	166.9	147.6
Gains on dispositions on property									1.0	1.1	0.0
Cost of revenues and operating costs									142.7	168.8	146.2
Operating Profit (Loss)									(142.7)	(168.8)	(146.2)
Other (income) expense									(16.9)	(158.6)	(128.8)
Equity in earnings of subsidiaries, net of taxes									300.0	617.1	353.7
Income (loss) before income taxes									174.2	606.9	336.3
Provision (benefit) for income taxes									(1.1)	(86.9)	16.0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									175.3	693.8	320.3
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									(16.0)	8.7	23.3
Net income from continuing operations									159.3	702.5	343.6
Net income attributable to noncontrolling interest									0.0	0.0	0.0
Net income (loss) attributable to controlling interest									159.3	702.5	343.6
Other comprehensive income									(5.8)	8.3	0.6
Comprehensive income									153.5	710.8	344.2
Comprehensive income attributable to noncontrolling interest									0.0	0.0	0.0
Comprehensive income attributable to controlling interest									153.5	710.8	344.2
Reportable legal entities | Combined Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues									1,631.7	1,649.6	2,386.1
Cost of revenues									1,395.6	1,314.6	1,893.8
Selling, engineering, and administrative expenses									107.2	124.3	117.5
Gains on dispositions on property									15.7	71.0	11.1
Cost of revenues and operating costs									1,487.1	1,367.9	2,000.2
Operating Profit (Loss)									144.6	281.7	385.9
Other (income) expense									38.1	122.4	109.0
Equity in earnings of subsidiaries, net of taxes									107.5	59.3	45.8
Income (loss) before income taxes									214.0	218.6	322.7
Provision (benefit) for income taxes									44.2	(310.2)	143.5
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									169.8	528.8	179.2
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									0.0	0.0	0.0
Net income from continuing operations									169.8	528.8	179.2
Net income attributable to noncontrolling interest									0.0	0.0	0.0
Net income (loss) attributable to controlling interest									169.8	528.8	179.2
Other comprehensive income									(0.4)	0.2	0.1
Comprehensive income									169.4	529.0	179.3
Comprehensive income attributable to noncontrolling interest									0.0	0.0	0.0
Comprehensive income attributable to controlling interest									169.4	529.0	179.3
Reportable legal entities | Combined Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues									1,291.7	1,096.6	1,152.6
Cost of revenues									988.4	831.2	890.7
Selling, engineering, and administrative expenses									47.7	48.1	48.8
Gains on dispositions on property									24.7	13.3	3.9
Cost of revenues and operating costs									1,011.4	866.0	935.6
Operating Profit (Loss)									280.3	230.6	217.0
Other (income) expense									142.3	209.1	188.7
Equity in earnings of subsidiaries, net of taxes									0.0	0.0	0.0
Income (loss) before income taxes									138.0	21.5	28.3
Provision (benefit) for income taxes									15.5	5.8	7.1
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									122.5	15.7	21.2
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									70.1	94.7	138.2
Net income from continuing operations									192.6	110.4	159.4
Net income attributable to noncontrolling interest									0.0	0.0	0.0
Net income (loss) attributable to controlling interest									192.6	110.4	159.4
Other comprehensive income									(7.0)	2.8	4.3
Comprehensive income									185.6	113.2	163.7
Comprehensive income attributable to noncontrolling interest									0.0	0.0	0.0
Comprehensive income attributable to controlling interest									185.6	113.2	163.7
Eliminations
Condensed Income Statements, Captions [Line Items]
Revenues									(414.3)	(348.8)	(448.9)
Cost of revenues									(447.2)	(373.6)	(471.1)
Selling, engineering, and administrative expenses									0.0	0.0	0.0
Gains on dispositions on property									0.0	0.0	0.0
Cost of revenues and operating costs									(447.2)	(373.6)	(471.1)
Operating Profit (Loss)									32.9	24.8	22.2
Other (income) expense									0.0	0.0	0.0
Equity in earnings of subsidiaries, net of taxes									(407.5)	(676.4)	(399.5)
Income (loss) before income taxes									(374.6)	(651.6)	(377.3)
Provision (benefit) for income taxes									(16.0)	(23.5)	(59.8)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									(358.6)	(628.1)	(317.5)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									0.0	0.0	0.0
Net income from continuing operations									(358.6)	(628.1)	(317.5)
Net income attributable to noncontrolling interest									3.8	11.1	21.1
Net income (loss) attributable to controlling interest									(362.4)	(639.2)	(338.6)
Other comprehensive income									0.0	0.0	0.0
Comprehensive income									(358.6)	(628.1)	(317.5)
Comprehensive income attributable to noncontrolling interest									5.2	13.7	24.2
Comprehensive income attributable to controlling interest									$ (363.8)	$ (641.8)	$ (341.7)