Revenue Recognition (Impact on Balance Sheet and Operating Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Accounts receivable - trade, net	$ 419,903		$ 447,421	$ 495,449
Inventories	95,667		93,791	88,653
Other assets, net of amortization	116,190		115,832	56,628
LIABILITIES AND CAPITAL
Other long-term liabilities	290,401		276,435	256,571
Partner's capital	1,951,590		2,022,597	$ 2,026,147
OPERATING INCOME
Total revenues	725,808
Operating Income	59,081	$ 52,597
Offshore Pipeline Transportation
OPERATING INCOME
Total revenues	73,260
Cost of revenues	18,340
Sodium Minerals & Sulfur Services
OPERATING INCOME
Total revenues	285,910
Cost of revenues	223,498
Marine Transportation
OPERATING INCOME
Total revenues	48,929
Cost of revenues	37,847
Onshore Facilities & Transportation
OPERATING INCOME
Total revenues	317,709
Onshore Facilities & Transportation | Onshore facilities and transportation product costs
OPERATING INCOME
Cost of revenues	277,818
Onshore Facilities & Transportation | Onshore facilities and transportation operating costs
OPERATING INCOME
Cost of revenues	22,295
Adjustment/Without adoption of ASC 606 | Accounting Standards Update 2014-09
ASSETS
Accounts receivable - trade, net	472,116
Inventories	92,628
Other assets, net of amortization	51,948
LIABILITIES AND CAPITAL
Other long-term liabilities	268,832
Partner's capital	1,958,091
OPERATING INCOME
Total revenues	704,714
Operating Income	62,032
Adjustment/Without adoption of ASC 606 | Accounting Standards Update 2014-09 | Offshore Pipeline Transportation
OPERATING INCOME
Total revenues	74,111
Cost of revenues	18,340
Adjustment/Without adoption of ASC 606 | Accounting Standards Update 2014-09 | Sodium Minerals & Sulfur Services
OPERATING INCOME
Total revenues	263,965
Cost of revenues	199,454
Adjustment/Without adoption of ASC 606 | Accounting Standards Update 2014-09 | Marine Transportation
OPERATING INCOME
Total revenues	48,929
Cost of revenues	37,847
Adjustment/Without adoption of ASC 606 | Accounting Standards Update 2014-09 | Onshore Facilities & Transportation
OPERATING INCOME
Total revenues	317,709
Adjustment/Without adoption of ASC 606 | Accounting Standards Update 2014-09 | Onshore Facilities & Transportation | Onshore facilities and transportation product costs
OPERATING INCOME
Cost of revenues	277,818
Adjustment/Without adoption of ASC 606 | Accounting Standards Update 2014-09 | Onshore Facilities & Transportation | Onshore facilities and transportation operating costs
OPERATING INCOME
Cost of revenues	22,295
Effect of Change Increase/(Decrease)
OPERATING INCOME
Total revenues	21,094
Operating Income	(2,951)
Effect of Change Increase/(Decrease) | Offshore Pipeline Transportation
OPERATING INCOME
Total revenues	(851)
Cost of revenues	0
Effect of Change Increase/(Decrease) | Sodium Minerals & Sulfur Services
OPERATING INCOME
Total revenues	21,945
Cost of revenues	24,044
Effect of Change Increase/(Decrease) | Marine Transportation
OPERATING INCOME
Total revenues	0
Cost of revenues	0
Effect of Change Increase/(Decrease) | Onshore Facilities & Transportation
OPERATING INCOME
Total revenues	0
Effect of Change Increase/(Decrease) | Onshore Facilities & Transportation | Onshore facilities and transportation product costs
OPERATING INCOME
Cost of revenues	0
Effect of Change Increase/(Decrease) | Onshore Facilities & Transportation | Onshore facilities and transportation operating costs
OPERATING INCOME
Cost of revenues	0
Effect of Change Increase/(Decrease) | Accounting Standards Update 2014-09
ASSETS
Accounts receivable - trade, net	(52,213)		(48,028)
Inventories	3,039		5,138
Other assets, net of amortization	64,242		59,204
LIABILITIES AND CAPITAL
Other long-term liabilities	21,569		19,864
Partner's capital	$ (6,501)		$ (3,550)