BUSINESS COMBINATION - PROFORMA (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pro-forma Combined
Operating revenue	$ 507.0	$ 559.1	$ 1,457.5	$ 1,569.5
Net income	$ 28.2	$ 38.3	$ 67.7	$ 68.9
Basic Earnings Per Share (in dollars per share)	$ 0.66	$ 0.88	$ 1.57	$ 1.58
Diluted Earnings Per Share (in dollars per share)	$ 0.66	$ 0.87	$ 1.56	$ 1.57
Weighted Average Number of Shares Outstanding:
Basic	42.8	43.5	43.1	43.5
Diluted	43.2	44.0	43.5	44.0

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

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