Segments and Related Information (Schedule of Financial Information by Reportable Segment - EBITDA) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
EBITDA:
EBITDA	$ 95.3	$ 53.8	$ 141.5	$ 96.6
Reportable Segments [Member] | Communications [Member]
EBITDA:
EBITDA	66.4	40.5	128.1	92.2
Reportable Segments [Member] | Oil and Gas [Member]
EBITDA:
EBITDA	53.6	41.3	69.8	62.9
Reportable Segments [Member] | Electrical Transmission [Member]
EBITDA:
EBITDA	(9.9)	(21.4)	(33.7)	(23.9)
Reportable Segments [Member] | Power Generation and Industrial [Member]
EBITDA:
EBITDA	4.8	8.0	7.7	(0.9)
Reportable Segments [Member] | Other [Member]
EBITDA:
EBITDA	0.3	0.0	0.5	(5.1)
Corporate [Member]
EBITDA:
EBITDA	$ (19.9)	$ (14.6)	$ (30.9)	$ (28.6)