Financial Statements for Guarantors of the Senior Notes (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, Captions [Line Items]
Revenues	$ 1,547.0	$ 1,542.2	$ 1,676.8	$ 1,626.7	$ 1,661.4	$ 1,562.8	$ 1,485.3	$ 1,460.5	$ 6,392.7	$ 6,170.0	$ 4,365.3
Cost of revenues	1,116.1	1,109.4	1,219.6	1,211.1	1,275.3	1,172.2	1,098.3	1,074.0	4,656.2	4,619.8	3,322.3
Selling, engineering, and administrative expenses	137.1	126.6	114.4	98.3	110.6	113.0	96.4	83.6	476.4	403.6	291.3
Gains on dispositions on property	64.2	58.7	40.1	15.8	1.0	3.6	11.4	88.4	178.8	104.4	21.2
Cost of revenues and operating costs									4,953.8	4,919.0	3,592.4
Operating Profit (Loss)	358.0	364.9	382.9	333.1	276.5	281.2	302.0	391.3	1,438.9	1,251.0	772.9
Other (income) expense									186.9	186.9	182.4
Equity in earnings of subsidiaries, net of taxes									0.0	0.0	0.0
Income from continuing operations before income taxes									1,252.0	1,064.1	590.5
Provision (benefit) for income taxes									426.0	354.8	204.4
Net income from continuing operations									826.0	709.3	386.1
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0.0	0.0	6.3
Net income	204.0	212.2	220.8	189.0	146.3	156.9	173.1	233.0	826.0	709.3	392.4
Net income attributable to noncontrolling interest									29.5	31.1	16.9
Net income attributable to controlling interest	200.0	204.3	212.0	180.2	138.2	149.4	164.2	226.4	796.5	678.2	375.5
Net income	$ 204.0	$ 212.2	$ 220.8	$ 189.0	$ 146.3	$ 156.9	$ 173.1	$ 233.0	826.0	709.3	392.4
Other comprehensive income (loss)									(0.5)	(31.0)	74.7
Comprehensive income									825.5	678.3	467.1
Comprehensive income attributable to noncontrolling interest									32.5	34.1	21.1
Comprehensive income attributable to controlling interest									793.0	644.2	446.0
Reportable legal entities | Parent
Condensed Income Statements, Captions [Line Items]
Revenues									0.0	0.0	0.0
Cost of revenues									(2.0)	2.3	0.6
Selling, engineering, and administrative expenses									147.0	115.6	72.7
Gains on dispositions on property									2.0	(1.4)	0.3
Cost of revenues and operating costs									143.0	119.3	73.0
Operating Profit (Loss)									(143.0)	(119.3)	(73.0)
Other (income) expense									(118.7)	(60.3)	(71.5)
Equity in earnings of subsidiaries, net of taxes									920.0	741.7	378.6
Income from continuing operations before income taxes									895.7	682.7	377.1
Provision (benefit) for income taxes									99.2	4.5	1.6
Net income from continuing operations									796.5	678.2	375.5
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0.0	0.0	0.0
Net income									796.5	678.2	375.5
Net income attributable to noncontrolling interest									0.0	0.0	0.0
Net income attributable to controlling interest									796.5	678.2	375.5
Net income									796.5	678.2	375.5
Other comprehensive income (loss)									(6.0)	(33.9)	48.2
Comprehensive income									790.5	644.3	423.7
Comprehensive income attributable to noncontrolling interest									0.0	0.0	0.0
Comprehensive income attributable to controlling interest									790.5	644.3	423.7
Reportable legal entities | Combined Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues									4,668.8	4,290.3	2,768.5
Cost of revenues									3,594.9	3,345.5	2,227.5
Selling, engineering, and administrative expenses									153.3	124.9	87.4
Gains on dispositions on property									86.0	41.3	11.1
Cost of revenues and operating costs									3,662.2	3,429.1	2,303.8
Operating Profit (Loss)									1,006.6	861.2	464.7
Other (income) expense									68.6	57.1	40.5
Equity in earnings of subsidiaries, net of taxes									217.4	191.8	84.6
Income from continuing operations before income taxes									1,155.4	995.9	508.8
Provision (benefit) for income taxes									353.2	297.2	160.7
Net income from continuing operations									802.2	698.7	348.1
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0.0	0.0	0.0
Net income									802.2	698.7	348.1
Net income attributable to noncontrolling interest									0.0	0.0	0.0
Net income attributable to controlling interest									802.2	698.7	348.1
Net income									802.2	698.7	348.1
Other comprehensive income (loss)									0.0	(8.5)	8.4
Comprehensive income									802.2	690.2	356.5
Comprehensive income attributable to noncontrolling interest									0.0	0.0	0.0
Comprehensive income attributable to controlling interest									802.2	690.2	356.5
Reportable legal entities | Combined Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues									2,642.6	2,700.2	2,237.7
Cost of revenues									2,005.3	2,098.5	1,740.2
Selling, engineering, and administrative expenses									176.1	163.1	131.9
Gains on dispositions on property									90.8	64.5	9.8
Cost of revenues and operating costs									2,090.6	2,197.1	1,862.3
Operating Profit (Loss)									552.0	503.1	375.4
Other (income) expense									237.0	190.1	213.4
Equity in earnings of subsidiaries, net of taxes									0.0	0.0	0.0
Income from continuing operations before income taxes									315.0	313.0	162.0
Provision (benefit) for income taxes									12.5	50.6	40.0
Net income from continuing operations									302.5	262.4	122.0
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0.0	0.0	6.3
Net income									302.5	262.4	128.3
Net income attributable to noncontrolling interest									0.0	0.0	0.0
Net income attributable to controlling interest									302.5	262.4	128.3
Net income									302.5	262.4	128.3
Other comprehensive income (loss)									5.5	11.4	18.1
Comprehensive income									308.0	273.8	146.4
Comprehensive income attributable to noncontrolling interest									0.0	0.0	0.0
Comprehensive income attributable to controlling interest									308.0	273.8	146.4
Eliminations
Condensed Income Statements, Captions [Line Items]
Revenues									(918.7)	(820.5)	(640.9)
Cost of revenues									(942.0)	(826.5)	(646.0)
Selling, engineering, and administrative expenses									0.0	0.0	(0.7)
Gains on dispositions on property									0.0	0.0	0.0
Cost of revenues and operating costs									(942.0)	(826.5)	(646.7)
Operating Profit (Loss)									23.3	6.0	5.8
Other (income) expense									0.0	0.0	0.0
Equity in earnings of subsidiaries, net of taxes									(1,137.4)	(933.5)	(463.2)
Income from continuing operations before income taxes									(1,114.1)	(927.5)	(457.4)
Provision (benefit) for income taxes									(38.9)	2.5	2.1
Net income from continuing operations									(1,075.2)	(930.0)	(459.5)
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0.0	0.0	0.0
Net income									(1,075.2)	(930.0)	(459.5)
Net income attributable to noncontrolling interest									29.5	31.1	16.9
Net income attributable to controlling interest									(1,104.7)	(961.1)	(476.4)
Net income									(1,075.2)	(930.0)	(459.5)
Other comprehensive income (loss)									0.0	0.0	0.0
Comprehensive income									(1,075.2)	(930.0)	(459.5)
Comprehensive income attributable to noncontrolling interest									32.5	34.1	21.1
Comprehensive income attributable to controlling interest									$ (1,107.7)	$ (964.1)	$ (480.6)