Selected Quarterly Data (Unaudited) (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
Selected Quarterly Data (Unaudited)
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
Cost of sales	95,600,000	284.10	279.10	315.30	323.90	322,300,000	316,900,000	299,900,000	255,800,000	1,202,400,000	1,194,900,000	872,800,000
Net earnings (loss)	$ 7,100,000	$ (10,300,000)	$ (400,800,000)	$ 7,400,000	$ 17,900,000	$ (32,600,000)	$ 31,300,000	$ 45,400,000	$ 44,000,000	$ (385,800,000)	$ 88,100,000	$ 150,400,000
Basic net earnings per share	$ 0.14	$ (0.20)	$ (7.68)	$ 0.14	$ 0.34	$ (0.62)	$ 0.60	$ 0.87	$ 0.84	$ (7.39)	$ 1.69	$ 2.88
Diluted net earnings per share	$ 0.14	$ (0.20)	$ (7.68)	$ 0.14	$ 0.34	$ (0.62)	$ 0.60	$ 0.87	$ 0.84	$ (7.39)	$ 1.68	$ 2.88
Impairment charge			$ 640,200,000							$ 640,200,000
Goodwill impairment charge			310,400,000							310,400,000
Intangible assets impairment			177,800,000							$ 177,800,000
Property and equipment impairment			$ 152,000,000
Non-recurring costs		$ 32,400,000				$ 98,000,000	$ 26,200,000