Segment Reporting (Revenues and Operating Earnings Based on Originating Location) (Details) - USD ($)	1 Months Ended	3 Months Ended								12 Months Ended
	Jan. 31, 2015	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jan. 31, 2016	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 133,000,000	$ 358.20	$ 365.00	$ 412.70	$ 431.50	$ 440,700,000	$ 453,200,000	$ 430,900,000	$ 370,900,000	$ 1,567,400,000	$ 1,695,700,000	$ 1,291,600,000
Operating earnings	17,700,000									(536,800,000)	246,800,000	238,500,000
Identifiable assets	4,224,600,000	3,691,000,000				$ 4,280,600,000				3,691,000,000	4,280,600,000	3,064,000,000
Domestic
Segment Reporting Information [Line Items]
Revenues	124,100,000									1,453,400,000	1,505,300,000	1,116,600,000
Operating earnings	15,000,000									(561,000,000)	195,500,000	170,900,000
Identifiable assets	3,710,300,000	3,182,200,000								3,182,200,000
Foreign
Segment Reporting Information [Line Items]
Revenues	8,900,000									114,000,000	190,400,000	175,000,000
Operating earnings	2,700,000									24,200,000	51,300,000	67,600,000
Identifiable assets	514,300,000	$ 508,800,000								508,800,000
Export revenues from United States to customers in foreign countries	$ 29,600,000									$ 457,900,000	$ 414,300,000	$ 361,400,000