Financial Statements for Guarantors of the Senior Notes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Income Statements, Captions [Line Items]
Revenues	$ 1,661.4	$ 1,562.8	$ 1,485.3	$ 1,460.5	$ 1,256.0	$ 1,110.3	$ 1,066.1	$ 932.9	$ 6,170.0	$ 4,365.3	$ 3,811.9
Cost of revenues	1,275.3	1,172.2	1,098.3	1,074.0	962.7	836.3	812.2	711.1	4,619.8	3,322.3	3,051.5
Selling, engineering, and administrative expenses	110.6	113.0	96.4	83.6	80.2	70.6	71.5	69.0	403.6	291.3	224.1
Gains/(losses) on disposition of property, plant, and equipment	1.0	3.6	11.4	88.4	11.3	2.2	1.0	6.7	104.4	21.2	38.5
Cost of revenues and operating costs									4,919.0	3,592.4	3,237.1
Operating Profit (Loss)	276.5	281.2	302.0	391.3	224.4	205.6	183.4	159.5	1,251.0	772.9	574.8
Other (income) expense									186.9	182.4	188.9
Equity in earnings of subsidiaries, net of taxes									0	0	0
Income (loss) from continuing operations before income taxes									1,064.1	590.5	385.9
Provision (benefit) for income taxes									354.8	204.4	134.0
Income (loss) from continuing operations	146.4	156.3	173.3	233.3	118.9	105.8	89.2	72.2	709.3	386.1	251.9
Income (loss) from discontinued operations, net of provision (benefit) for income taxes	(0.1)	0.6	(0.2)	(0.3)	0.4	0.3	(1.0)	6.6	0	6.3	1.8
Net income (loss)	146.3	156.9	173.1	233.0	119.3	106.1	88.2	78.8	709.3	392.4	253.7
Net income (loss) attributable to noncontrolling interest									31.1	16.9	(1.5)
Net income (loss) attributable to controlling interest	138.2	149.4	164.2	226.4	112.8	99.6	84.0	79.1	678.2	375.5	255.2
Other comprehensive income (loss)									(31.0)	74.7	(14.5)
Comprehensive income									678.3	467.1	239.2
Parent
Condensed Income Statements, Captions [Line Items]
Revenues									0	0	0
Cost of revenues									0	0	0
Selling, engineering, and administrative expenses									115.6	72.8	50.4
Gains/(losses) on disposition of property, plant, and equipment									(1.4)	0.3	0.4
Cost of revenues and operating costs									117.0	72.5	50.0
Operating Profit (Loss)									(117.0)	(72.5)	(50.0)
Other (income) expense									(60.3)	(71.5)	(56.5)
Equity in earnings of subsidiaries, net of taxes									740.2	378.3	246.6
Income (loss) from continuing operations before income taxes									683.5	377.3	253.1
Provision (benefit) for income taxes									5.3	1.8	(2.1)
Income (loss) from continuing operations									678.2	375.5	255.2
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0	0	0
Net income (loss)									678.2	375.5	255.2
Net income (loss) attributable to noncontrolling interest									0	0	0
Net income (loss) attributable to controlling interest									678.2	375.5	255.2
Other comprehensive income (loss)									(32.2)	47.7	(20.1)
Comprehensive income									646.0	423.2	235.1
Combined Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues									4,725.4	3,257.8	2,791.5
Cost of revenues									3,705.3	2,636.3	2,385.3
Selling, engineering, and administrative expenses									151.5	128.9	111.4
Gains/(losses) on disposition of property, plant, and equipment									41.4	10.9	9.4
Cost of revenues and operating costs									3,815.4	2,754.3	2,487.3
Operating Profit (Loss)									910.0	503.5	304.2
Other (income) expense									86.3	61.2	49.0
Equity in earnings of subsidiaries, net of taxes									228.9	97.1	88.2
Income (loss) from continuing operations before income taxes									1,052.6	539.4	343.4
Provision (benefit) for income taxes									325.4	167.0	117.1
Income (loss) from continuing operations									727.2	372.4	226.3
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									(0.1)	6.3	1.4
Net income (loss)									727.1	378.7	227.7
Net income (loss) attributable to noncontrolling interest									0	0	0
Net income (loss) attributable to controlling interest									727.1	378.7	227.7
Other comprehensive income (loss)									(10.0)	9.9	(6.1)
Comprehensive income									717.1	388.6	221.6
Combined Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues									2,294.2	1,758.2	1,429.0
Cost of revenues									1,770.2	1,341.9	1,087.9
Selling, engineering, and administrative expenses									136.5	90.3	62.3
Gains/(losses) on disposition of property, plant, and equipment									64.4	10.0	28.7
Cost of revenues and operating costs									1,842.3	1,422.2	1,121.5
Operating Profit (Loss)									451.9	336.0	307.5
Other (income) expense									160.9	192.7	196.4
Equity in earnings of subsidiaries, net of taxes									0	0	0
Income (loss) from continuing operations before income taxes									291.0	143.3	111.1
Provision (benefit) for income taxes									26.1	33.5	14.3
Income (loss) from continuing operations									264.9	109.8	96.8
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0.1	0	0.4
Net income (loss)									265.0	109.8	97.2
Net income (loss) attributable to noncontrolling interest									0	0	0
Net income (loss) attributable to controlling interest									265.0	109.8	97.2
Other comprehensive income (loss)									11.2	17.1	11.7
Comprehensive income									276.2	126.9	108.9
Eliminations
Condensed Income Statements, Captions [Line Items]
Revenues									(849.6)	(650.7)	(408.6)
Cost of revenues									(855.7)	(655.9)	(421.7)
Selling, engineering, and administrative expenses									0	(0.7)	0
Gains/(losses) on disposition of property, plant, and equipment									0	0	0
Cost of revenues and operating costs									(855.7)	(656.6)	(421.7)
Operating Profit (Loss)									6.1	5.9	13.1
Other (income) expense									0	0	0
Equity in earnings of subsidiaries, net of taxes									(969.1)	(475.4)	(334.8)
Income (loss) from continuing operations before income taxes									(963.0)	(469.5)	(321.7)
Provision (benefit) for income taxes									(2.0)	2.1	4.7
Income (loss) from continuing operations									(961.0)	(471.6)	(326.4)
Income (loss) from discontinued operations, net of provision (benefit) for income taxes									0	0	0
Net income (loss)									(961.0)	(471.6)	(326.4)
Net income (loss) attributable to noncontrolling interest									31.1	16.9	(1.5)
Net income (loss) attributable to controlling interest									(992.1)	(488.5)	(324.9)
Other comprehensive income (loss)									0	0	0
Comprehensive income									$ (961.0)	$ (471.6)	$ (326.4)