Derivative Financial Instruments (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014 item	Sep. 30, 2013	Sep. 30, 2014 item	Sep. 30, 2013	Dec. 31, 2013 item	Dec. 31, 2012
Fair values of derivatives on consolidated balance sheets
Maximum period covering risk of changes in supply of gas prices			18 months
Open derivative contracts for natural gas (in MMBtus)	117,200,000		117,200,000		76,300,000
Percentage of natural gas consumption covered by derivatives			85.00%
Aggregate fair value of the derivative instruments with credit risk related contingent features in a net liability position	$ 20,400,000		$ 20,400,000		$ 200,000
Authorized expenditure for construction of new ammonia and urea/UAN production units						3,800,000,000
Unrealized (losses) gains
Derivatives not designated as hedges	(15,500,000)	14,300,000	(79,900,000)	10,800,000
Cash flow hedge ineffectiveness		1,300,000		(800,000)
Total unrealized (losses) gains	(15,500,000)	15,600,000	(79,900,000)	10,000,000
Realized gains	(20,100,000)	(7,400,000)	77,400,000	1,900,000
Net derivative (losses) gains	(35,600,000)	8,200,000	(2,500,000)	11,900,000
Cash collateral on deposit with derivative counterparties	0		0		0
Foreign exchange contracts
Fair values of derivatives on consolidated balance sheets
Notional amount of derivative	328,400,000		328,400,000		636,300,000
Derivatives not designated as cash flow hedges
Unrealized (losses) gains
Derivatives not designated as hedges	(15,500,000)	14,300,000	(79,900,000)	10,800,000
Derivatives not designated as cash flow hedges | Natural gas derivatives | Cost of Sales
Unrealized (losses) gains
Derivatives not designated as hedges	12,100,000	(5,600,000)	(39,100,000)	(1,200,000)
Derivatives not designated as cash flow hedges | Foreign exchange contracts | Other operating - net
Unrealized (losses) gains
Derivatives not designated as hedges	(27,600,000)	19,900,000	(40,800,000)	12,000,000
Derivatives designated as cash flow hedges | Foreign exchange contracts
Fair values of derivatives on consolidated balance sheets
Notional amount of derivative	0		0
Gain (loss) recognized in OCI		6,100,000		(400,000)
Gain (loss) reclassified from AOCI into income	2,800,000
Derivatives designated as cash flow hedges | Foreign exchange contracts | Other operating - net
Unrealized (losses) gains
Net derivative (losses) gains		$ 1,300,000		$ (800,000)