Revenue Recognition (Impact on Balance Sheet and Operating Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Accounts receivable - trade, net	$ 365,646		$ 365,646		$ 447,421	$ 495,449
Inventories	85,722		85,722		93,791	88,653
Other assets, net of amortization	120,102		120,102		115,832	56,628
LIABILITIES AND CAPITAL
Other long-term liabilities	275,823		275,823		276,435	256,571
Partners' capital	1,799,409		1,799,409		2,022,597	$ 2,026,147
OPERATING INCOME
Total revenues	745,278		2,223,474
Operating Income	46,148	$ 43,100	166,129	$ 157,144
Offshore Pipeline Transportation
OPERATING INCOME
Total revenues	70,115		213,344
Cost of revenues	17,753		53,533
Sodium Minerals & Sulfur Services
OPERATING INCOME
Total revenues	291,722		876,513
Cost of revenues	229,204		685,219
Marine Transportation
OPERATING INCOME
Total revenues	56,296		161,410
Cost of revenues	44,195		126,259
Onshore facilities and transportation
OPERATING INCOME
Total revenues	327,145		972,207
Onshore facilities and transportation | Onshore facilities and transportation product costs
OPERATING INCOME
Cost of revenues	273,251		834,128
Onshore facilities and transportation | Onshore facilities and transportation operating costs
OPERATING INCOME
Cost of revenues	22,005		67,346
Effect of Change Increase/(Decrease)
OPERATING INCOME
Total revenues	24,307		80,461
Operating Income	(884)		2,527
Effect of Change Increase/(Decrease) | Offshore Pipeline Transportation
OPERATING INCOME
Total revenues	792		5,271
Cost of revenues	0		0
Effect of Change Increase/(Decrease) | Sodium Minerals & Sulfur Services
OPERATING INCOME
Total revenues	23,515		75,190
Cost of revenues	25,191		77,934
Effect of Change Increase/(Decrease) | Marine Transportation
OPERATING INCOME
Total revenues	0		0
Cost of revenues	0		0
Effect of Change Increase/(Decrease) | Onshore facilities and transportation
OPERATING INCOME
Total revenues	0		0
Effect of Change Increase/(Decrease) | Onshore facilities and transportation | Onshore facilities and transportation product costs
OPERATING INCOME
Cost of revenues	0		0
Effect of Change Increase/(Decrease) | Onshore facilities and transportation | Onshore facilities and transportation operating costs
OPERATING INCOME
Cost of revenues	0		0
Accounting Standards Update 2014-09 | Adjustments
ASSETS
Accounts receivable - trade, net	413,674		413,674
Inventories	83,329		83,329
Other assets, net of amortization	50,742		50,742
LIABILITIES AND CAPITAL
Other long-term liabilities	251,075		251,075
Partners' capital	1,800,432		1,800,432
OPERATING INCOME
Total revenues	720,971		2,143,013
Operating Income	47,032		163,602
Accounting Standards Update 2014-09 | Adjustments | Offshore Pipeline Transportation
OPERATING INCOME
Total revenues	69,323		208,073
Cost of revenues	17,753		53,533
Accounting Standards Update 2014-09 | Adjustments | Sodium Minerals & Sulfur Services
OPERATING INCOME
Total revenues	268,207		801,323
Cost of revenues	204,013		607,285
Accounting Standards Update 2014-09 | Adjustments | Marine Transportation
OPERATING INCOME
Total revenues	56,296		161,410
Cost of revenues	44,195		126,259
Accounting Standards Update 2014-09 | Adjustments | Onshore facilities and transportation
OPERATING INCOME
Total revenues	327,145		972,207
Accounting Standards Update 2014-09 | Adjustments | Onshore facilities and transportation | Onshore facilities and transportation product costs
OPERATING INCOME
Cost of revenues	273,251		834,128
Accounting Standards Update 2014-09 | Adjustments | Onshore facilities and transportation | Onshore facilities and transportation operating costs
OPERATING INCOME
Cost of revenues	22,005		67,346
Accounting Standards Update 2014-09 | Effect of Change Increase/(Decrease)
ASSETS
Accounts receivable - trade, net	(48,028)		(48,028)		(48,028)
Inventories	2,393		2,393		5,138
Other assets, net of amortization	69,360		69,360		59,204
LIABILITIES AND CAPITAL
Other long-term liabilities	24,748		24,748		19,864
Partners' capital	$ (1,023)		$ (1,023)		$ (3,550)