Acquisitions (Assets Acquired and Liabilities Assumed - Vinnolit) (Details) - USD ($) $ in Thousands	Jul. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$ 62,016	$ 62,016	$ 62,016
Vinnolit [Member]
Business Acquisition [Line Items]
Cash paid to Sellers	$ 309,619
Cash deposited in escrow	13,390
Retirement of long-term debt as of July 31, 2014, on behalf of the Sellers	413,215
Total purchase consideration	736,224
Cash	125,137
Working capital, excluding inventory and cash	15,373
Inventories	114,961
Property, plant and equipment	469,484
Investments	51,552
Other assets	76,828
Deferred income tax asset - current	7,909
Deferred income tax asset - non-current	27,387
Pension obligation	(117,970)
Other long-term liabilities	(10,723)
Power purchase agreement liability	(10,826)
Deferred income tax liability - current	(6,845)
Deferred income tax liability - non-current	(79,235)
Total identifiable net assets	736,224
Goodwill	0
Consideration transferred	736,224
Fair value of accounts receivable	181,890
Gross contractual amount of accounts receivable	183,833
Uncollectable accounts receivable	1,943
Adjustment to inventory fair value	$ 16,900
Weighted-average life of forward purchase contracts	3 years
Trademarks and Trade Names [Member] | Vinnolit [Member]
Business Acquisition [Line Items]
Intangible assets	$ 40,170
Developed Technology Rights [Member] | Vinnolit [Member]
Business Acquisition [Line Items]
Intangible assets	31,600
Other [Member] | Vinnolit [Member]
Business Acquisition [Line Items]
Intangible assets	$ 1,422