Acquisitions (Schedule of Purchase Price Allocation) (Details) - USD ($) $ in Thousands	Sep. 01, 2017	Jul. 24, 2015
Alkali Business [Member]
Business Acquisition [Line Items]
Accounts receivable	$ 138,258
Inventories	34,929
Other current assets	13,254
Fixed assets	663,217
Mineral leaseholds	566,019
Intangible assets	800
Other assets	3,612
Accounts payable	(44,547)
Accrued liabilities	(36,884)
Other long-term liabilities	(13,658)
Total purchase price	$ 1,325,000
Enterprise Offshore Acquisition [Member]
Business Acquisition [Line Items]
Cash		$ 1,270
Accounts receivable		29,768
Inventories		600
Other current assets		10,432
Fixed assets		1,225,685
Intangible assets		79,050
Equity investees		352,535
Other assets		1,966
Accounts payable		(6,110)
Accrued liabilities		(18,662)
Other long-term liabilities		(161,412)
Noncontrolling interest		6,447
Total purchase price		$ 1,521,569