Consolidated Statements Of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net sales:
Other income	$ 0.5	$ 0.0	$ 0.9
Total	397.2	418.3	581.7
Cost of goods sold:
Materials, supplies and services	212.6	163.6	228.0
Gross margin	156.7	226.8	325.8
Other general and administrative expenses	1.7	1.9	3.2
Gain on sale of equity method investment	(14.3)	0.0	0.0
Operating Income (Loss)	153.4	209.2	306.9
Interest Income, Other	0.5	0.1	0.0
Net earnings	153.9	209.3	306.9
Allocation of net earnings:
Net earnings	$ 153.9	$ 209.3	$ 306.9
Net earnings per Common Unit (in dollars per unit)	$ 5.93	$ 7.56	$ 10.06
Affiliate of General Partner
Net sales:
Product sales to affiliates of the General Partner	$ 396.1	$ 417.7	$ 580.2
Other income	0.6	0.6	0.6
Cost of goods sold:
Services provided by affiliates of the General Partner	27.9	27.9	27.9
Selling, general and administrative services provided by affiliates of the General Partner	15.9	15.7	15.7
General Partner's Interest
Allocation of net earnings:
Net Income Allocated to General Partners	42.6	67.4	117.7
Common Units | Class B Common
Allocation of net earnings:
Net Income Allocated to Limited Partners	1.5	2.0	3.0
Common Units | Common units
Allocation of net earnings:
Net Income Allocated to Limited Partners	$ 109.8	$ 139.9	$ 186.2