Rentech (RTK) 10-Q 11 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	RTK
Entity Registrant Name	RENTECH, INC.
Entity Central Index Key	868725
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		229,483,306

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets
Cash	$53,747	$44,195
Accounts receivable, including unbilled revenue, net of allowance for doubtful accounts of $800 and $500 at March 31, 2015 and December 31, 2014, respectively	30,346	33,619
Inventories	53,294	38,085
Prepaid expenses and other current assets	13,284	11,142
Deferred income taxes	1,870	1,870
Other receivables, net	8,252	10,715
Assets of discontinued operations	110	305
Total current assets	160,903	139,931
Property, plant and equipment, net	470,674	392,451
Construction in progress	110,540	179,423
Other assets
Goodwill	40,255	38,393
Intangible assets	61,081	61,804
Debt issuance costs	10,195	9,631
Deposits and other assets	4,760	4,840
Assets of discontinued operations	1,677	1,677
Total other assets	117,968	116,345
Total assets	860,085	828,150
Current liabilities
Accounts payable	24,588	31,439
Accrued payroll and benefits	8,317	7,185
Accrued liabilities	30,990	37,406
Deferred revenue	47,107	28,607
Current portion of long term debt	18,652	17,784
Accrued interest	10,864	5,018
Earn-out consideration		5,000
Other	2,538	2,601
Liabilities of discontinued operations	1,206	1,711
Total current liabilities	144,262	136,751
Long-term liabilities
Debt	488,464	451,072
Earn-out consideration	1,184	1,295
Asset retirement obligation	4,484	4,404
Deferred income taxes	11,286	9,850
Other	5,488	5,883
Total long-term liabilities	510,906	472,504
Total liabilities	655,168	609,255
Commitments and contingencies (Note 14)
Stockholders' equity
Common stock: $.01 par value; 450,000 shares authorized; 229,427 and 229,308 shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	2,294	2,293
Additional paid-in capital	542,803	543,091
Accumulated deficit	-420,980	-417,349
Accumulated other comprehensive loss	-16,602	-7,302
Total Rentech stockholders' equity	107,515	120,733
Noncontrolling interests	2,147	3,102
Total equity	109,662	123,835
Total liabilities and stockholders' equity	860,085	828,150
Series E Preferred Stock [Member]
Mezzanine equity
Preferred stock	95,255	95,060
Series A Convertible Preferred Shares [Member]
Stockholders' equity
Preferred stock
Series C Participating Cumulative Preferred Stock [Member]
Stockholders' equity
Preferred stock
Series D Junior Participating Preferred Stock [Member]
Stockholders' equity
Preferred stock

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Allowance for accounts receivable	$800	$500
Preferred stock, par value	$10	$10
Mezzanine, preferred stock, dividend rate	4.50%
Preferred stock, shares authorized	1,000,000	1,000,000
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	229,427,000	229,308,000
Common stock, shares outstanding	229,427,000	229,308,000
Series E Preferred Stock [Member]
Mezzanine, preferred stock, par value	$10	$10
Mezzanine, preferred stock, shares authorized	100,000,000	100,000,000
Mezzanine, preferred stock, shares issued	100,000,000	100,000,000
Mezzanine, preferred stock, shares outstanding	100,000,000	100,000,000
Mezzanine, preferred stock, dividend rate	4.50%	4.50%
Series A Convertible Preferred Shares [Member]
Preferred stock, shares authorized	90,000	90,000
Preferred stock, shares issued	90,000	90,000
Preferred stock, shares outstanding	0	0
Preferred stock, liquidation preference per share	$0	$0
Series C Participating Cumulative Preferred Stock [Member]
Preferred stock, par value	$10	$10
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series D Junior Participating Preferred Stock [Member]
Preferred stock, par value	$10	$10
Preferred stock, shares authorized	45,000	45,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues
Product sales	$88,468	$63,548
Service revenues	16,603	18,247
Other revenues	539	524
Total revenues	105,610	82,319
Cost of sales
Product	67,971	49,887
Service	13,330	14,537
Total cost of sales	81,301	64,424
Gross profit	24,309	17,895
Operating expenses
Selling, general and administrative expense	14,504	15,572
Depreciation and amortization	1,874	-324
Other income	-3	-348
Total operating expenses	16,375	14,900
Operating income	7,934	2,995
Other expense, net
Interest expense	-5,917	-5,845
Other expense, net	-115	-24
Total other expenses, net	-6,032	-5,869
Income (loss) from continuing operations before income taxes and equity in loss of investee	1,902	-2,874
Income tax expense	1,694	1,050
Income (loss) from continuing operations before equity in loss of investee	208	-3,924
Equity in loss of investee	15	199
Income (loss) from continuing operations	193	-4,123
Loss from discontinued operations, net of tax	-147	-1,471
Net income (loss)	46	-5,594
Net income attributable to noncontrolling interests	-3,675	-1,394
Preferred stock dividends	-1,320
Net loss attributable to Rentech common shareholders	($4,949)	($6,988)
Basic and diluted:
Continuing operations	($0.02)	($0.02)
Discontinued operations	$0	($0.01)
Net Loss	($0.02)	($0.03)
Weighted-average shares used to compute net loss per common share:
Basic	229,362	227,529
Diluted	229,362	227,529

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$46	($5,594)
Other comprehensive income (loss), net of tax:
Pension and postretirement plan adjustments	4	-12
Foreign currency translation	-9,302	-1,087
Other comprehensive loss	-9,298	-1,099
Comprehensive loss	-9,252	-6,693
Less: net income attributable to noncontrolling interests	-3,675	-1,394
Less: other comprehensive (income) loss attributable to noncontrolling interests	-2	5
Comprehensive loss attributable to Rentech	($12,929)	($8,082)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (Unaudited) (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Rentech Stockholders' Equity [Member]	Noncontrolling Interests [Member]
In Thousands
Beginning balance at Dec. 31, 2013	$167,956	$2,275	$541,254	($385,339)	($117)	$158,073	$9,883
Beginning balance, Shares at Dec. 31, 2013		227,512
Common stock issued for stock options exercised	33	1	32			33
Common stock issued for stock options exercised, Shares		52
Distributions to noncontrolling interests	-792						-792
Equity-based compensation expense	1,846		1,647			1,647	199
Restricted stock units	-2		-2			-2
Restricted stock units, Shares		1
Net income (loss)	-5,594			-6,988		-6,988	1,394
Other comprehensive income (loss)	-1,099				-1,094	-1,094	-5
Other	-15						-15
Ending balance at Mar. 31, 2014	162,333	2,276	542,931	-392,327	-1,211	151,669	10,664
Ending balance, Shares at Mar. 31, 2014		227,565
Beginning balance at Dec. 31, 2014	123,835	2,293	543,091	-417,349	-7,302	120,733	3,102
Beginning balance, Shares at Dec. 31, 2014		229,308
Common stock issued for stock options exercised	5	1	4			5
Common stock issued for stock options exercised, Shares		118
Dividends - preferred stock	-1,320		-1,320			-1,320
Distributions to noncontrolling interests	-4,763						-4,763
Equity-based compensation expense	1,160		1,029			1,029	131
Restricted stock units	-1		-1			-1
Restricted stock units, Shares		1
Net income (loss)	46			-3,629		-3,629	3,675
Other comprehensive income (loss)	-9,298				-9,300	-9,300	2
Other	-2			-2		-2
Ending balance at Mar. 31, 2015	$109,662	$2,294	$542,803	($420,980)	($16,602)	$107,515	$2,147
Ending balance, Shares at Mar. 31, 2015		229,427

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities
Net income (loss)	$46	($5,594)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	9,823	4,441
Utilization of spare parts	1,314	2,387
Non-cash interest expense	113	170
Equity-based compensation	1,160	1,846
Unrealized net gain on derivatives	-2,604
Other	96	-310
Changes in operating assets and liabilities, net of amounts acquired:
Accounts receivable	3,219	-8,864
Other receivables	1,614	-1,837
Inventories	-13,633	-16,753
Prepaid expenses and other current assets	-1,713	595
Other assets	-238	-695
Accounts payable	-3,067	9,851
Deferred revenue	18,500	28,930
Accrued interest	5,632	4,994
Accrued liabilities, accrued payroll and other	1,438	-2,581
Net cash provided by operating activities	21,700	16,580
Cash flows from investing activities
Capital expenditures	-30,071	-38,907
Payment for acquisitions, net of cash received	-7,214
Other items	3	-182
Net cash used in investing activities	-37,282	-39,089
Cash flows from financing activities
Proceeds from debt and credit facilities	39,244	407
Payments of debt	-4,954	-2,528
Payment of earn-out consideration	-3,840
Distributions to noncontrolling interests	-4,763	-792
Other	-522	33
Net cash provided by (used in) financing activities	25,165	-2,880
Effect of exchange rate on cash	-31	-218
Increase (decrease) in cash	9,552	-25,607
Cash, beginning of period	44,195	106,369
Cash, end of period	53,747	80,762
Purchase of property, plant, equipment and construction in progress in accounts payable and accrued liabilities	15,123	14,892
Fair value of assets in acquisition	7,241
Fair value of liabilities assumed in acquisition	27
Increase in QS Construction Facility obligation	5,850	1,633
Accrued dividends on preferred stock	$1,125

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Note 1 — Basis of Presentation
	The accompanying unaudited consolidated financial statements of Rentech, Inc. (“Rentech”) and its consolidated subsidiaries (collectively, the “Company”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in compliance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Neither authority requires all of the information and footnotes required by GAAP for complete financial statements. Accordingly, the accompanying financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, considered necessary for a fair statement of the Company’s financial position as of March 31, 2015, and the results of operations and cash flows for the periods presented. The accompanying consolidated financial statements include the accounts of Rentech, its wholly owned subsidiaries and all subsidiaries in which Rentech directly or indirectly owns a controlling financial interest. All significant intercompany accounts and transactions have been eliminated in consolidation. Operating results for the three months ended March 31, 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 or any other reporting period. The information included in this Form 10-Q should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 filed with the Securities and Exchange Commission (the “SEC”) on March 16, 2015 (the “Annual Report”).
	The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Liquidity
	During the next 12 months, the Company expects the liquidity needs of its wood fibre processing business, including announced ongoing construction projects, and of its corporate activities to be met from: (i) cash on hand, (ii) distributions from Rentech Nitrogen Partners, L.P. (“RNP”), (iii) cash generated by its wood fibre processing business, (iv) borrowings under the A&R GSO Credit Agreement, as defined in Note 13 — Debt, and (v) in the case of capital expenditures and working capital in Chile, Chilean bank debt financing. The Company expects that it would need to seek additional funds from its investors or in the capital markets if any of the following circumstances occur: (i) the sources of funds summarized above in this paragraph were less than expected, (ii) its expenses, including capital expenditures to commission the Atikokan Project and to complete and commission the Wawa Project, as defined in Note 11 — Property, Plant and Equipment, were higher than expected, (iii) the cash flow from the Atikokan or Wawa Facilities, as defined in Note 11 — Property, Plant and Equipment, were less than or later than expected, or (iv) the Company were to approve new capital projects, enter into additional commitments or acquire assets in addition to those that could be funded from the sources identified above. The Company may not be able to obtain funding in the equity or debt capital markets on terms it finds acceptable if it were to need such financing. A potential additional source of capital that could be available to fund shortfalls in the event of the possible circumstances mentioned above or to enhance expected liquidity would be the sale of some or all of the 3.1 million unpledged common units of RNP that the Company owns.

Revision_of_Previously_Reporte

Revision of Previously Reported Revenues and Cost of Sales	3 Months Ended
	Mar. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Revision of Previously Reported Revenues and Cost of Sales	Note 2 — Revision of Previously Reported Revenues and Cost of Sales
	In filings that covered reporting periods during 2013 and 2014, the Company incorrectly reported revenues and cost of sales for Fulghum’s South America operations. Certain intercompany transactions between two of Fulghum’s Chilean subsidiaries were not eliminated in consolidation. As a result, both revenues and cost of sales were overstated for 2013 by approximately $4.7 million and 2014 by approximately $7.1 million. The Company has revised the first quarter 2014 amounts contained in this filing to properly reflect the elimination of the intercompany transactions. For the three months ended March 31, 2014, revenues and cost of goods sold were reduced by $2.5 million from amounts previously reported with no impact to gross profit or net income. Management does not believe the impact of these errors was material to the first quarter of 2014, the full year results of 2014 or any previously issued financial statements.
		For the Years Ended
		December 31,
		2014			2013
		(in thousands)
	As Reported:
	Revenues	$	472,661		$	374,349
	Product sales		400,282			322,022
	Service revenues		70,317			49,822
	Cost of sales		392,987			290,963
	Product cost of sales		335,544			252,741
	Service cost of sales		57,443			38,222
	Effect of Revisions:
	Revenues	$	(7,101	)	$	(4,690	)
	Product sales		(7,101	)		(3,060	)
	Service revenues		—			(1,630	)
	Cost of sales		(7,101	)		(4,690	)
	Product cost of sales		(7,101	)		(3,060	)
	Service cost of sales		—			(1,630	)
	As Revised:
	Revenues	$	465,560		$	369,659
	Product sales		393,181			318,962
	Service revenues		70,317			48,192
	Cost of sales		385,886			286,273
	Product cost of sales		328,443			249,681
	Service cost of sales		57,443			36,592
		For the Three Months Ended
		March 31,			June 30,						September 30,						December 31,
		2014			2014			2013			2014			2013			2014			2013
		(in thousands)
	As Reported:
	Revenues	$	84,831		$	139,890		$	120,061		$	125,304		$	115,657		$	122,636		$	79,067
	Product sales		65,345			123,007			107,545			106,802			96,621			105,128			59,132
	Service revenues		18,962			16,425			11,732			17,955			18,608			16,975			19,482
	Cost of sales		66,936			108,451			77,788			112,335			94,513			105,265			81,817
	Product cost of sales		51,684			94,455			68,254			97,880			80,272			91,525			67,370
	Service cost of sales		15,252			13,996			9,534			14,455			14,241			13,740			14,447
	Effect of Revisions:
	Revenues	$	(2,512	)	$	(690	)	$	(773	)	$	(3,132	)	$	(1,511	)	$	(767	)	$	(2,406	)
	Product sales		(1,797	)		(1,405	)		(488	)		(3,132	)		(945	)		(767	)		(1,627	)
	Service revenues		(715	)		715			(285	)		—			(566	)		—			(779	)
	Cost of sales		(2,512	)		(690	)		(773	)		(3,132	)		(1,511	)		(767	)		(2,406	)
	Product cost of sales		(1,797	)		(1,405	)		(488	)		(3,132	)		(945	)		(767	)		(1,627	)
	Service cost of sales		(715	)		715			(285	)		—			(566	)		—			(779	)
	As Revised:
	Revenues	$	82,319		$	139,200		$	119,288		$	122,172		$	114,146		$	121,869		$	76,661
	Product sales		63,548			121,602			107,057			103,670			95,676			104,361			57,505
	Service revenues		18,247			17,140			11,447			17,955			18,042			16,975			18,703
	Cost of sales		64,424			107,761			77,015			109,203			93,002			104,498			79,411
	Product cost of sales		49,887			93,050			67,766			94,748			79,327			90,758			65,743
	Service cost of sales		14,537			14,711			9,249			14,455			13,675			13,740			13,668
		For the Six Months Ended						For the Nine Months Ended
		June 30,						September 30,
		2014			2013			2014			2013
		(in thousands)						(in thousands)
	As Reported:
	Revenues	$	224,721		$	179,625		$	350,025		$	295,282
	Product sales		188,352			166,269			295,154			262,890
	Service revenues		35,387			11,732			53,342			30,340
	Cost of sales		175,387			114,633			287,722			209,146
	Product cost of sales		146,139			105,099			244,019			185,371
	Service cost of sales		29,248			9,534			43,703			23,775
	Effect of Revisions:
Revenues	$	(3,202	)	$	(773	)	$	(6,334	)	$	(2,284	)
Product sales		(3,202	)		(488	)		(6,334	)		(1,433	)
Service revenues		—			(285	)		—			(851	)
Cost of sales		(3,202	)		(773	)		(6,334	)		(2,284	)
Product cost of sales		(3,202	)		(488	)		(6,334	)		(1,433	)
Service cost of sales		—			(285	)		—			(851	)
As Revised:
Revenues	$	221,519		$	178,852		$	343,691		$	292,998
Product sales		185,150			165,781			288,820			261,457
Service revenues		35,387			11,447			53,342			29,489
Cost of sales		172,185			113,860			281,388			206,862
Product cost of sales		142,937			104,611			237,685			183,938
Service cost of sales		29,248			9,249			43,703			22,924

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Note 3 — Recent Accounting Pronouncements
	In April 2014, the Financial Accounting Standards Board (the “FASB”) issued guidance that provides a narrower definition of discontinued operations than under previous guidance. It requires that only disposals of components of an entity (or groups of components) that represent a strategic shift that has or will have a major effect on the reporting entity’s operations are to be reported in the financial statements as discontinued operations. It also provides guidance on the financial statement presentations and disclosures of discontinued operations. This guidance is effective prospectively for disposals (or classifications of held-for-sale) of components of an entity that occur in annual or interim periods beginning after December 15, 2014. The impact of this guidance is dependent on whether or not future disposals occur.
	In May 2014, the FASB issued guidance that will significantly enhance comparability of revenue recognition practices across entities, industries, jurisdictions, and capital markets. In April 2015, FASB proposed a one-year deferral of the effective date to annual reporting periods beginning on or after December 15, 2017. In addition, the FASB proposal would include an option to early adopt the guidance for annual periods beginning on or after December 15, 2016. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosures.
	In June 2014, the FASB issued guidance on accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the requisite service period. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosures.
	In August 2014, the FASB issued guidance on presentation of financial statements — going concern, which applies to all companies. It requires management to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. This guidance is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosure.
	In November 2014, the FASB issued guidance on hybrid financial instruments. The guidance does not change the current criteria for determining when separation of certain embedded derivative features in a hybrid financial instrument is required. The guidance clarifies that an entity should consider all relevant terms and features, including the embedded derivative feature being evaluated for bifurcation, in evaluating the nature of the host contract. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosures.
	In January 2015, the FASB issued guidance that eliminates the concept of extraordinary items. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosures.
	In February 2015, the FASB issued guidance that changes the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosures.
	In April 2015, the FASB issued guidance, which would require that debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of debt liability, consistent with debt discounts or premiums. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosures.
	In April 2015, the FASB issued guidance that will help entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement. If a cloud computing arrangement includes a software license, then the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. This guidance is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2015. The Company is evaluating the provisions of this guidance and the potential impact, if any, on its consolidated financial position, results of operations and disclosures.

Acquisition

Acquisition	3 Months Ended
	Mar. 31, 2015
Wood Pellets NEWP [Member]
Acquisition	Note 5 — NEWP Acquisition
	On May 1, 2014, the Company acquired all of the equity interests of NEWP (the “NEWP Acquisition”). The final purchase price consisted of $35.4 million of cash as well as earn-out consideration of $5.0 million, which was paid in cash during the three months ended March 31, 2015.
	This business combination was accounted for using the acquisition method of accounting, which requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date.
	The final purchase price recognized in our financial statements consisted of the following (amounts in thousands):
	Cash		$	35,434
	Earn-out consideration(1)			5,000
	Total final purchase price		$	40,434
	-1	As of December 31, 2014, the earn-out consideration of $5.0 million was earned, and during the three months ended March 31, 2015, it was paid.
	The Company’s final purchase price allocation is as follows (amounts in thousands):
	Cash		$	3,852
	Accounts receivable			2,925
	Inventories			2,239
	Prepaid expenses and other current assets			439
	Property, plant and equipment			30,625
	Intangible assets (trade name - $5,000, customer relationships - $1,900, and non-compete agreements - $200)			7,100
	Goodwill			8,461
	Accounts payable			(1,641	)
	Accrued liabilities			(442	)
	Customer deposits			(882	)
	Loans			(12,600	)
	Interest rate swaps			(802	)
	Total preliminary purchase price(2)		$	39,274
	-2	The difference between the final purchase price of $40.4 million and the preliminary purchase price of $39.3 million is the $1.1 million of additional earn-out consideration, which was recorded subsequent to the closing date of the NEWP Acquisition in the consolidated statement of operations.
	Intangible assets consist primarily of customer relationships, trade names and non-compete agreements with former owners. The estimated useful life of each of the trade names is 20 years, 13 years for customer relationships and three years for non-compete agreements.
	The goodwill recorded reflects the value to Rentech of NEWP’s market position, of entry into the residential and commercial heating markets, and of the increases in Rentech’s product offerings, customer bases and geographic markets. The goodwill recorded as part of this acquisition is amortizable for tax purposes.
	NEWP’s operations are included in the consolidated statements of operations as of May 1, 2014. See “Note 6 — Pro Forma Information” for unaudited pro forma information relating to the NEWP Acquisition.
Allegheny [Member]
Acquisition	Note 4 — Allegheny Acquisition
	On January 23, 2015, our subsidiary, New England Wood Pellet, LLC (“NEWP”), acquired for $7.2 million substantially all of the assets of Allegheny Pellet Corporation (“Allegheny”), which consist of a wood pellet processing facility located in Youngsville, Pennsylvania, (the “Allegheny Acquisition”). The Company financed the purchase with a five-year, $8.0 million term loan. The proceeds from the term loan not used for the purchase price of Allegheny will be used for transaction costs and capital expenditures related to environmental and safety improvements at the Allegheny facility.
	The acquisition is considered a business combination and has been accounted for using the acquisition method of accounting, which requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date.
	The Company’s preliminary purchase price allocation is as follows (amounts in thousands):
	Inventories		$	214
	Property, plant and equipment			3,937
	Construction in progress			28
	Intangible assets (customer relationships - $800 and trade name - $400)			1,200
	Goodwill			1,862
	Accrued liabilities			(27	)
	Total purchase price		$	7,214
	Intangible assets consist of customer relationships and the trade name. The estimated useful life for each of the customer relationships and trade name is 15 years.
	The goodwill recorded reflects the value to Rentech of Allegheny’s market position, and of the increases in Rentech’s product offerings, customer bases and geographic markets in the Allegheny Acquisition. The goodwill recorded as part of this acquisition is amortizable for tax purposes.
	The final purchase price and the allocation thereof will not be known until the valuation of intangible assets is completed, which is expected to be during the fourth quarter of 2015.
	Allegheny’s operations are included in the consolidated statements of operations as of January 23, 2015. During the three months ended March 31, 2015, the Company recorded revenue of $1.2 million and gross profit of $0.1 million related to Allegheny. See “Note 6 — Pro Forma Information” for unaudited pro forma information relating to the Allegheny Acquisition.

Pro_Forma_Information

Pro Forma Information	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
Pro Forma Information	Note 6 — Pro Forma Information
	The unaudited pro forma information has been prepared as if the Allegheny Acquisition and the NEWP Acquisition had taken place on January 1, 2014. The unaudited pro forma information is not necessarily indicative of the results that the Company would have achieved had the transactions actually taken place on January 1, 2014, and the unaudited pro forma information does not purport to be indicative of future financial operating results.
		For the Three Months Ended March 31, 2015
		As Reported			Pro Forma		Pro Forma
					Adjustments
		(in thousands)
	Revenues	$	105,610		$	389	$	105,999
	Net income	$	46		$	155	$	201
	Net income (loss) attributable to Rentech	$	(4,949	)	$	155	$	(4,794	)
	Basic and diluted net income (loss) from continuing operations per common share allocated to Rentech	$	(0.02	)	$	0	$	(0.02	)
		For the Three Months Ended March 31, 2014
		As Reported			Pro Forma		Pro Forma
					Adjustments
		(in thousands)
	Revenues	$	82,319		$	12,601	$	94,920
	Net income (loss)	$	(5,594	)	$	962	$	(4,632	)
	Net income (loss) attributable to Rentech	$	(6,988	)	$	962	$	(6,026	)
	Basic and diluted net income (loss) from continuing operations per common share allocated to Rentech	$	(0.02	)	$	0	$	(0.02	)

Discontinued_Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Note 7 — Discontinued Operations
	The Company’s consolidated balance sheets and consolidated statements of operations for all periods presented in this report reflect the energy technologies segment as discontinued operations. In the consolidated statements of cash flows, the cash flows of discontinued operations are not separately classified or aggregated, and are reported in the respective categories with those of continuing operations.
	All discussions and amounts in the consolidated financial statements and related notes, except for cash flows, for all periods presented relate to continuing operations only, unless otherwise noted. Any ongoing activities related to our alternative energy technologies will be to maintain our Commerce City site until it is sold and the natural gas pipeline at Natchez until it is abandoned.
	The following table summarizes the components of assets and liabilities of discontinued operations.
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Prepaid expenses and other current assets	$	110		$	305
	Total current assets	$	110		$	305
	Property held for sale	$	1,677		$	1,677
	Total other assets	$	1,677		$	1,677
	Total assets	$	1,787		$	1,982
	Accounts payable	$	32		$	144
	Accrued payroll and benefits		223			559
	Accrued liabilities		264			1,008
	Other		687			—
	Total liabilities	$	1,206		$	1,711
	The following table summarizes the results of discontinued operations.
		For the Three Months Ended
		March 31,
		2015			2014
		(in thousands)
	Revenues	$	56		$	156
	Operating loss	$	(147	)	$	(1,498	)
	Loss from discontinued operations, net of tax	$	(147	)	$	(1,471	)

Fair_Value

Fair Value	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value	Note 8 — Fair Value
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants and is classified in one of the following three categories:
		•		Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date.
		•		Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data.
		•		Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
	Fair values of cash, receivables, deposits, other current assets, accounts payable, accrued liabilities and other current liabilities were assumed to approximate carrying value since they are short term and can be settled on demand.
	The following table presents the financial instruments that were accounted for at fair value by level as of March 31, 2015 and December 31, 2014.
			Level 1			Level 2			Level 3
			(in thousands)
	Liabilities
	Earn-out consideration — March 31, 2015		$	—		$	—		$	1,184
	Earn-out consideration — December 31, 2014		$	—		$	—		$	1,295
	The following table presents the fair value and carrying value of the Company’s borrowings as of March 31, 2015.
			Fair Value									Carrying Value
			(in thousands)
			Level 1			Level 2			Level 3
	Liabilities
	RNP Notes		$	311,002		$	—		$	—		$	320,000
	Fulghum debt			—			49,333			—			53,020
	NEWP debt			—			18,357			—			18,607
	A&R GSO Credit Agreement			—			75,000			—			73,700
	GE Credit Agreement			—			19,000			—			19,000
	The following table presents the fair value and carrying value of the Company’s borrowings as of December 31, 2014.
			Fair Value									Carrying Value
			(in thousands)
			Level 1			Level 2			Level 3
	Liabilities
	RNP Notes		$	310,202		$	—		$	—		$	320,000
	Fulghum debt			—			53,192			—			54,771
	NEWP debt			—			10,968			—			11,265
	A&R GSO Credit Agreement			—			50,000			—			49,142
	GE Credit Agreement			—			15,000			—			15,000
	Earn-out Consideration
	At March 31, 2015, the earn-out consideration includes $1.2 million of potential earn-out consideration relating to the Atikokan Project. This consideration is deemed to be a Level 3 financial instrument because the measurement is based on unobservable inputs. The fair value of earn-out consideration was determined based on the Company’s analysis of various scenarios involving the achievement of certain levels of EBITDA, as defined in the asset purchase agreement related to the Atikokan Project, over a ten-year period. The scenarios, which included a weighted probability factor, involved assumptions relating to product profitability and production levels. The earn-out consideration will be measured at each reporting date with changes in its fair value recognized in the consolidated statements of operations. Assuming the minimum required EBITDA level is achieved, an increase or decrease of $1.0 million in EBITDA would result in an increase or decrease in earn-out consideration of $0.1 million. The Company provided a loan to the sellers in the Atikokan Project of $0.7 million, which will be repaid plus accrued interest from any earn-out consideration. The collectibility of the loan is tied to the amount of earn-out consideration the sellers receive from the Company.
	A reconciliation of the change in the carrying value of the earn-out consideration during 2015 is as follows:
			Atikokan			NEWP			Total
			(in thousands)
	Balance at December 31, 2014		$	1,295		$	5,000		$	6,295
	Add: Unrealized gain on foreign currency translation			(111	)		—			(111	)
	Less: Earn-out consideration payment			—			(5,000	)		(5,000	)
	Balance at March 31, 2015		$	1,184		$	—		$	1,184
	A reconciliation of the change in the carrying value of the earn-out consideration during 2014 is as follows:
			Atikokan
			(in thousands)
	Balance at December 31, 2013		$	1,544
	Add: Unrealized gain			(58	)
	Balance at March 31, 2014		$	1,486
	Debt Valuation
	The $320.0 million of 6.5% second lien senior secured notes due 2021 (the “RNP Notes”) are deemed to be Level 1 financial instruments because there was an active market for such debt. The fair value of such debt was determined based on market prices.
	The Fulghum debt and NEWP debt are deemed to be Level 2 financial instruments because the measurements are based on observable market data. The Company’s valuation reflects discounted expected future cash flows, which incorporate yield curves for instruments with similar characteristics, such as credit ratings, weighted average lives and maturity dates.
	The A&R GSO Credit Agreement and RNP’s credit agreement with General Electric Capital Corporation (the “GE Credit Agreement”) are deemed to be Level 2 financial instruments because the measurements are based on observable market data. The Company concluded that the carrying value of the A&R GSO Credit Agreement and GE Credit Agreement approximates the fair value of such loans as of March 31, 2015 and December 31, 2014 based on their floating interest rates and the Company’s assessment that the fixed-rate margins are still at market levels.
	The levels within the fair value hierarchy at which the Company’s financial instruments have been evaluated have not changed for any of the Company’s financial instruments during the three months ended March 31, 2015 and 2014.

Derivative_Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Note 9 — Derivative Instruments
	Accounting guidance establishes accounting and reporting requirements for derivative instruments and hedging activities. This guidance requires recognition of all derivative instruments as assets or liabilities on the Company’s consolidated balance sheets and measurement of those instruments at fair value. The accounting treatment of changes in fair value is dependent upon whether or not a derivative instrument is designated as a hedge and if so, the type of hedge. The Company currently does not designate any of its derivatives as hedges for financial accounting purposes. Gains and losses on derivative instruments not designated as hedges are currently included in earnings and reported under cash flows from operating activities.
	Forward Natural Gas Contracts
	RNP uses commodity-based derivatives to minimize its exposure to the fluctuations in natural gas prices. RNP recognizes the unrealized gains or losses related to the commodity-based derivative instruments in its consolidated financial statements. RNP does not have any master netting agreements or collateral relating to these derivatives.
	Our East Dubuque Facility enters into forward natural gas purchase contracts to reduce its exposure to the fluctuations in natural gas prices. The forward natural gas contracts are deemed to be Level 2 financial instruments because the measurement is based on observable market data. The fair value of such contracts had been determined based on market prices. Gain or loss associated with forward natural gas contracts is recorded in cost of sales on the consolidated statements of operations. The amount of unrealized gain recorded was $2.6 million for the three months ended March 31, 2015. There was no unrealized gain or loss for the three months ended March 31, 2014.
	Interest Rate Swaps
	NEWP entered into three interest rate swaps in notional amounts that cover the borrowings under its two industrial revenue bonds and a real estate mortgage loan.
	Under the interest rate swaps, NEWP pays interest at a fixed rate of 5.29% on the outstanding balance of one of the industrial revenue bonds, 5.05% on the outstanding balance of the other industrial revenue bond and 7.95% on the outstanding balance of the real estate mortgage loan. NEWP receives interest at the variable interest rates specified in the various swap agreements.
	Through the interest rate swaps, NEWP is essentially fixing the variable interest rate to be paid on these borrowings.
	The interest rate swaps are designated as derivatives for accounting purposes. The interest rate swaps are deemed to be Level 2 financial instruments because the measurements are based on observable market data. The Company used a standard swap contract valuation method to value its interest rate derivatives, and the inputs it uses for present value discounting included forward one-month LIBOR rates, risk-free interest rates and an estimate of credit risk. The fair value of the interest rate swaps at March 31, 2015 and December 31, 2014 represents the unrealized loss of $0.6 million and $0.7 million, respectively. Any adjustments to the fair value of the interest rate swaps from the date of the NEWP Acquisition will be recorded on the consolidated statements of operations.
	Net gain (loss) on interest rate swaps:
		For the Three
		Months
		Ended March 31,
		2015
	Realized loss	$	—
	Unrealized gain (loss)		24
	Total net gain (loss) on interest rate swaps	$	24
	The forward natural gas contracts are recorded in accrued liabilities on the consolidated balance sheets.
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Forward natural gas contracts recorded in current liabilities:
	Gross amounts recognized	$	1,382		$	3,955
	Gross amounts offset in consolidated balance sheets		(7	)		—
	Net amounts presented in the consolidated balance sheets	$	1,375		$	3,955
	The interest rate swaps are recorded in other liabilities on the consolidated balance sheets.
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Interest rate swaps recorded in current liabilities:
	Gross amounts recognized	$	629		$	653
	Gross amounts offset in consolidated balance sheets		—			—
	Net amounts presented in the consolidated balance sheets	$	629		$	653
	The following table presents the financial instruments that were accounted for at fair value by level as of March 31, 2015:
		Level 1			Level 2		Level 3
		(in thousands)
	Liabilities
	Forward gas contracts	$	—		$	1,375	$	—
	Interest rate swaps		—			629		—
	The following table presents the financial instruments that were accounted for at fair value by level as of December 31, 2014:
		Level 1			Level 2		Level 3
		(in thousands)
	Liabilities
	Forward gas contracts	$	—		$	3,955	$	—
	Interest rate swaps		—			653		—

Inventories

Inventories	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Note 10 — Inventories
	Inventories consisted of the following:
		As of
		March 31,		December 31,
		2015		2014
		(in thousands)
	Finished goods	$	39,157	$	26,669
	Raw materials		13,899		11,226
	Other		238		190
	Total inventory	$	53,294	$	38,085

Property_Plant_and_Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Note 11 — Property, Plant and Equipment
	Property, plant and equipment consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Land and land improvements	$	28,072		$	28,042
	Buildings and building improvements		46,486			45,516
	Machinery and equipment		490,249			406,489
	Furniture, fixtures and office equipment		1,782			1,610
	Computer equipment and computer software		10,384			8,748
	Vehicles		7,149			5,893
	Leasehold improvements		2,454			2,405
	Other		1,453			1,453
			588,029			500,156
	Less: Accumulated depreciation		(117,355	)		(107,705	)
	Total property, plant and equipment, net	$	470,674		$	392,451
	Construction in progress consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	East Dubuque Facility	$	14,790		$	15,010
	Pasadena Facility		207			32,747
	Fulghum Fibres		2,135			7,197
	Atikokan Project		—			36,931
	Wawa Project		66,944			65,232
	Construction under QS Construction Facility		25,698			21,712
	Other		766			594
	Total construction in progress	$	110,540		$	179,423
	The construction in progress balance includes $5.4 million of capitalized interest costs at March 31, 2015, and $6.3 million at December 31, 2014.
	The Company is in the process of converting an idled oriented strand board processing mill in Wawa, Ontario, Canada to a wood pellet facility (the “Wawa Facility”) designed to produce 450,000 metric tons of wood pellets annually (the “Wawa Project”). The Company is also in the process of converting a former particle board processing mill in Atikokan, Ontario, Canada to a wood pellet facility (the “Atikokan Facility”) and expects it to produce 110,000 metric tons of wood pellets annually (the “Atikokan Project”). The Atikokan Facility is in commissioning.

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Note 12 — Goodwill
	A reconciliation of the change in the carrying value of goodwill is as follows:
		Fulghum		NEWP		Total
		(in thousands)
	Balance at December 31, 2014	$	29,932	$	8,461	$	38,393
	Add: Allegheny Acquisition		—		1,862		1,862
	Balance at March 31, 2015	$	29,932	$	10,323	$	40,255
	At March 31, 2015 and December 31, 2014, the Company had accumulated impairment charges of $57.2 million related to the Pasadena Facility.

Debt

Debt	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Debt	Note 13 — Debt
	Amended and Restated Credit Agreement
	On February 12, 2015, Rentech Nitrogen Holdings, Inc. (“RNHI”) entered into the Amended and Restated Term Loan Credit Agreement among RNHI, certain funds managed by or affiliated with GSO Capital Partners LP, as lenders (“GSO Capital”), and Credit Suisse AG, Cayman Islands Branch, as administrative agent (the “A&R GSO Credit Agreement”). The A&R GSO Credit Agreement consists of three tranches of term loans, all of which mature on April 9, 2019: (i) a $50 million term loan originally drawn on April 16, 2014 (“Tranche A Loans”), (ii) an up to $45 million delayed draw term loan facility (“Tranche B Loans”) and (iii) an up to $18 million delayed draw term loan facility (“Tranche C Loans,” and together with the Tranche A Loans and the Tranche B Loans, the “Loans” ). The Company expects that the Tranche B Loans will be used to fund the development of its wood pellet projects in Ontario, Canada, and that the Tranche C Loans will be used to fund (x) in the event the ammonia converter at the Company’s East Dubuque, Illinois facility fails during the first year after the date of the A&R GSO Credit Agreement, any shortfall in cash distributions made by RNP to the Company resulting from unplanned downtime at the facility and the cost of repairs to the ammonia converter in such period (such funding not to exceed $13 million) and (y) in the event that cash distributions made by RNP to the Company for any quarter during the year ending December 31, 2015 are less than the budgeted amounts by a certain percentage, and such shortfall is due primarily to any combination of lower product prices and higher raw material prices (other than raw material prices which have been locked in through advance purchase or hedging transactions), the amount of such cash shortfall (such funding not to exceed $5 million).
	Of the amounts available, $25 million of the Tranche B Loans was drawn on February 12, 2015. The remainder of the Tranche B Loans and the Tranche C Loans must be drawn, if at all, by February 12, 2016. Tranche A Loans under the A&R GSO Credit Agreement bear interest at a rate equal to the greater of (i) LIBOR plus 7.00% and (ii) 8.00% per annum. Tranche B Loans and Tranche C Loans under the A&R GSO Credit Agreement bear interest at a rate equal to the greater of (i) LIBOR plus 9.00% and (ii) 10.00% per annum. In the event the Borrower prepays any of the Loans on or prior to February 12, 2016, subject to certain exceptions, it will be required to pay a prepayment fee equal to 1.00% of the amount of the prepayment.
	The Borrower’s obligations under the A&R GSO Credit Agreement are guaranteed by the Company and the Company’s direct and indirect subsidiaries other than RNP, the subsidiaries of RNP and certain other excluded subsidiaries (such subsidiaries guaranteeing obligations under the A&R GSO Credit Agreement, the “Subsidiary Guarantors,” and together with the Company and the Borrower, the “Loan Parties”). The obligations under the A&R GSO Credit Agreement and the guarantees are secured by a lien on substantially all of the Loan Parties’ tangible and intangible property, and by a pledge of all of the shares of stock and limited liability company interests owned by the Loan Parties, of which the Loan Parties now own or later acquire more than a 50% interest, subject to certain exceptions.
	The obligations of the Borrower under the A&R GSO Credit Agreement are also secured by 10,682,246 common units of RNP owned by the Borrower. The Loans are subject to a 2.00% original issue discount at the time of a draw.
	The A&R GSO Credit Agreement allows for dividends to be paid to the Company’s shareholders as long as there is no event of default and consent is given by GSO Capital.
	NEWP Debt
	On January 23, 2015, NEWP entered into a five-year, $8.0 million term loan, which amortizes as if it had a seven-year maturity, with the unamortized balance due at maturity. The term loan has an interest rate of LIBOR plus 2.25%, and contains financial covenants that restrict dividends from NEWP to Rentech.
	Total Debt
	As of March 31, 2015, the Company was in compliance with its debt covenants. Total debt consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	RNP Notes	$	320,000		$	320,000
	QS Construction Facility		22,788			18,679
	Fulghum debt		51,592			53,179
	A&R GSO Credit Agreement		75,000			50,000
	NEWP debt		18,290			10,913
	GE Credit Agreement		19,000			15,000
	Total debt	$	506,670		$	467,771
	Plus: Unamortized net premium		446			1,085
	Less: Current portion		(18,131	)		(17,260	)
	Less: Current portion unamortized premium		(521	)		(524	)
	Long-term debt	$	488,464		$	451,072

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 14 — Commitments and Contingencies
	Natural Gas Forward Purchase Contracts
	The Company’s policy and practice are to enter into fixed-price forward purchase contracts for natural gas in conjunction with contracted nitrogen fertilizer product sales in order to substantially fix gross margin on those product sales contracts. The Company may also enter into a limited amount of additional fixed-price forward purchase contracts for natural gas in order to reduce monthly and seasonal gas price volatility. The Company occasionally enters into index-price contracts for the purchase of natural gas. The Company has entered into multiple natural gas forward purchase contracts for various delivery dates through December 31, 2015. Commitments for natural gas purchases consist of the following:
		As of
		March 31,		December 31,
		2015		2014
		(in thousands, except weighted
		average rate)
	MMBtus under fixed-price contracts		3,505		3,188
	MMBtus under index-price contracts		—		540
	Total MMBtus under contracts		3,505		3,728
	Commitments to purchase natural gas	$	10,508	$	15,568
	Weighted average rate per MMBtu based on the fixed rates and the indexes applicable to each contract	$	3	$	4.18
	As of March 31, 2015, deposits against these forward gas contracts were $0.7 million. During April 2015, the Company entered into additional fixed-quantity forward purchase contracts at fixed and indexed prices for various delivery dates through December 31, 2015. The total MMBtus associated with these additional forward purchase contracts are 1.6 million and the total amount of the purchase commitments is $4.1 million, resulting in a weighted average rate per MMBtu of $2.66 in these new commitments. The Company is required to make additional prepayments under these forward purchase contracts in the event that market prices fall below the purchase prices in the contracts.
	Contractual Obligations
	Wood Pellets
	On May 1, 2013, Rentech’s subsidiary that owns the Wawa Facility entered into a ten-year take-or-pay contract (the “Drax Contract”) with Drax Power Limited (“Drax”). Under the Drax Contract, such subsidiary is required to sell to Drax the first 400,000 metric tonnes of wood pellets per year produced from the Wawa Facility. In the event that it does not deliver wood pellets as required under the Drax Contract, the Rentech subsidiary that owns the Wawa Facility is required to pay Drax an amount equal to the positive difference, if any, between the contract price for the wood pellets and the price of any wood pellets Drax purchases in replacement. Rentech has guaranteed this obligation in an amount not to exceed $20.0 million.
	On February 25, 2015, the Company entered into an amendment (the “Amendment”) to the Drax Contract. The Amendment canceled all wood pellet deliveries in 2014 and reduces the required volume of wood pellets to be delivered to Drax in 2015 to 240,000 tonnes. In exchange for the cancelled deliveries and reduced volume commitments, the Company paid Drax a penalty of approximately $170,000, and agreed to provide price reductions totaling approximately $0.9 million on pellet shipments expected to be made to Drax in 2015. In the event such shipments are not made, the price reductions would become cash penalties payable to Drax, in addition to other penalties that may be due under the Drax Contract for such failed deliveries. Also, portions of the original 2015 pellet deliveries are being pushed to future years at 2015 pricing, which is expected to be lower than pricing in those future years under the original terms of the contract.
	Rentech’s subsidiary that owns the Atikokan Facility entered into a ten-year take-or-pay contract (the “OPG Contract”) with Ontario Power Generation (“OPG”) under which such subsidiary is required to deliver 45,000 metric tonnes of wood pellets annually. OPG has the option to increase required delivery of wood pellets from the Atikokan Facility to up to 90,000 metric tonnes annually.
	A Rentech subsidiary has contracted with Canadian National Railway Company (the “Canadian National Contract”) for all rail transportation of wood pellets from the Atikokan Facility and the Wawa Facility to the Port of Quebec. The Atikokan Facility is located 1,300 track miles and the Wawa Facility is located 1,100 track miles from the Port of Quebec. Under the Canadian National Contract, such subsidiary has committed to transport a minimum of 3,600 rail carloads annually for the duration of the long-term contract. Delivery shortfalls would result in a $1,000 per rail car penalty.
	Litigation
	The Company is party to litigation from time to time in the normal course of business. The Company accrues liabilities related to litigation only when it concludes that it is probable that it will incur costs related to such litigation, and can reasonably estimate the amount of such costs. In cases where the Company determines that it is not probable, but reasonably possible that it has a material obligation, it discloses such obligations and the possible loss or range of loss, if such estimate can be made. The outcome of the Company’s current litigation matters is not estimable or probable. The Company maintains insurance to cover certain actions and believes that resolution of its current litigation matters will not have a material adverse effect on the Company’s financial statements.
	Regulation
	The Company’s business is subject to extensive and frequently changing federal, state and local, environmental, health and safety regulations governing a wide range of matters, including the emission of air pollutants, the release of hazardous substances into the environment, the treatment and discharge of waste water and the storage, handling, use and transportation of the Company’s fertilizer products, raw materials, and other substances that are part of our operations. These laws include the Clean Air Act (the “CAA”), the federal Water Pollution Control Act, the Resource Conservation and Recovery Act, the Comprehensive Environmental Response, Compensation and Liability Act, the Toxic Substances Control Act, and various other federal, state and local laws and regulations. The laws and regulations to which the Company is subject are complex, change frequently and have tended to become more stringent over time. The ultimate impact on the Company’s business of complying with existing laws and regulations is not always clearly known or determinable due in part to the fact that the Company’s operations may change over time and certain implementing regulations for laws, such as the CAA, have not yet been finalized, are under governmental or judicial review or are being revised. These laws and regulations could result in increased capital, operating and compliance costs.
	The Company entered into a settlement agreement with the Illinois Environmental Protection Agency in August 2013 requiring it to connect a device at the East Dubuque Facility to an ammonia safety flare by December 1, 2015. The Company estimates the cost of the project required by the settlement agreement as being $0.4 million.
	The Company negotiated a settlement agreement with Region 6 of the Environmental Protection Agency relating to an ammonia release that occurred at the Pasadena Facility on April 20, 2014. The penalty required by the settlement agreement was $0.1 million.
	Gain and Loss Contingencies
	In 2014, the Board of Assessment Appeals State of Colorado determined that Adams County owes the Company a property tax refund of $1.2 million related to the 2013 tax year. Adams County has appealed to the Colorado Court of Appeals. The Company has not recorded the receivable and accrued interest related to the overpayment as it represents a gain contingency.
	For the 2014 tax year, Adams County has asserted that the Company owes $0.3 million more than the amount that the Company accrued. Because it won its appeal for 2013, the Company believes that the assessment of $0.4 million is not probable and has not reflected an accrual for the excess amount of $0.3 million.
	The Company expects the costs to abandon a pipeline that it owns in Natchez, Mississippi, to be $0.8 million. These costs were recorded in discontinued operations during the year ended December 31, 2014, but are expected to be incurred in 2015 to complete the abandonment process. The Company is entitled to reimbursement from the buyer of its property in Natchez for its costs relating to the pipeline abandonment. The Company has not recorded the receivable related to the reimbursement of abandonment costs as it represents a gain contingency.
	A fire at our mill in Maine during the first quarter of 2014 disrupted operations, causing lower processing volumes and higher than typical processing costs at the facility during the first half of 2014. The mill’s customer has indicated it incurred unspecified losses related to the production disruptions caused by the fire. The Company believes that any obligation to its customer related to the fire is not probable and has not recorded any potential liability from this contingency.
	Abener Teyma General Partnership (“Abeinsa”), the engineering, procurement and construction (“EPC”) contractor for the power generation facility at the Pasadena Facility, recently submitted to Rentech Nitrogen Pasadena, LLC (“RNPLLC”) approximately $10.0 million of change orders for approval and payment. Under the terms of the EPC contract between RNPLLC and Abeinsa (the “EPC Contract”), RNPLLC must agree to any change order for it to be effective. RNPLLC has contested the validity of these change orders and presented its own change orders, and claims for damages under the EPC Contract to Abeinsa. The parties are involved in the contractual dispute resolution process as to how to resolve the disputed change orders and other outstanding claims related to the construction of the power generation facility. The Company is unable at this time to estimate any potential liability from this contingency.
	Quebec Stevedoring Company Limited (“QSL”), the party that constructed wood pellet storage and handling facilities at the Port of Quebec for the Company (the “Quebec Port Project”), has submitted change orders to the Company in an amount estimated to be $2.3 million over the original cost for the project that the Company is contractually liable to pay. The obligation to QSL is denominated in Canadian dollars; the obligation recorded in U.S. dollars as of March 31, 2015 is $15.8 million. The Company expects to pay for these change orders by adding such amount to the remaining balance on the $15.8 million fifteen-year note used to finance the project. The parties have not yet finalized an agreement as to these change orders. In accordance with GAAP, the Company is considered the owner of the Quebec Port Project and has accordingly recorded the total amount of the project cost in construction in progress and a corresponding amount as project financing in debt. As such, the Company has recorded $22.8 million of debt under the Quebec Construction Facility (see Note 13 – Debt), of which, under the terms of the contract with QSL, the Company’s obligation is limited to $15.8 million, subject to approved change orders.

Preferred_Stock

Preferred Stock	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Preferred Stock	Note 15 — Preferred Stock
	In 2014, the Company entered into a Subscription Agreement (the “Subscription Agreement”) with funds managed by or affiliated with GSO Capital (the “Series E Purchasers”), pursuant to which the Company sold 100,000 shares of its Series E Convertible Preferred Stock (the “2014 Preferred Stock” or “Series E Preferred Stock”) to the Series E Purchasers. In addition, a newly formed wholly owned subsidiary of the Company, DSHC, LLC (“DSHC”), and each of the Series E Purchasers entered into a Put Option Agreement (the “Put Option Agreements”).
	The 2014 Preferred Stock is accounted for as mezzanine equity in the consolidated balance sheets. However, dividends are recorded in the consolidated statements of stockholders’ equity and consist of the 4.5% dividend plus the amortization of issuance costs and accretion of discount. Dividends are paid on the first business day of June and December of each year.
	Mezzanine equity consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Original issue price of 2014 Preferred Stock	$	100,000		$	100,000
	Less: Issuance costs		(3,020	)		(3,144	)
	Less: Unamortized discount		(1,725	)		(1,796	)
	Total mezzanine equity	$	95,255		$	95,060
	Amendment No. 1 to Subscription Agreement
	On February 12, 2015, the Company entered into an amendment to the Subscription Agreement with the Series E Purchasers (the “Subscription Agreement Amendment”). Among others things, the parties amended the Subscription Agreement as follows:
	Call Right. At any time, subject to certain conditions, the Company may elect to repurchase all of the 2014 Preferred Stock originally purchased under the Subscription Agreement (“Purchased Shares”) in exchange for (a) cash of $1,000 per Purchased Share (as adjusted for any stock splits, stock dividends, recapitalizations or the like), plus any accrued and unpaid dividends thereon and (b) warrants exercisable for the number of shares of Rentech’s common stock (“Common Stock”) equal to the number of shares of Common Stock into which such Series E Purchaser’s Purchased Shares are convertible (“Repurchase Warrants”). If issued, the Repurchase Warrants will have an exercise price equal to the conversion price of the Purchased Shares (the “Conversion Price”), which is $2.22 per share (subject to appropriate adjustment for stock splits, dividends, combinations, recapitalizations and the like).
	Additional Put Right. Upon the occurrence of an “RNP Change of Control,” as defined in the Subscription Agreement Amendment, each Series E Purchaser will have the right to cause the Company to purchase any or all of the outstanding Purchased Shares held by such Series E Purchaser for a price per Purchased Share equal to cash of $1,000 per Purchased Share (as adjusted for any stock splits, stock dividends, recapitalizations or the like), plus all accrued and unpaid dividends thereon. An “RNP Change of Control” generally is defined as (a) an event that constitutes a “Change of Control” as defined in the A&R GSO Credit Agreement that is not already a “Change of Control” under the Articles of Amendment of the Company setting forth the terms of the Purchased Shares, except that upon the repayment in full of the loans under the A&R GSO Credit Agreement, a sale, transfer, conveyance, encumbrance or other disposition of any capital stock or equity interests that constitutes collateral under the A&R GSO Credit Agreement will no longer be an “RNP Change of Control” or (b) any sale, transfer, conveyance, encumbrance (other than encumbrances created by the pledge agreement entered into by DSHC for the benefit of the Series E Purchasers) or other disposition by DSHC of any common units of RNP that are collateral under such pledge agreement to any person.
	Amended and Restated Put Option Agreements
	On February 12, 2015, DSHC entered into Amended and Restated Put Option Agreements with each of the Purchasers (the “ A&R Put Option Agreements”) pursuant to which certain rights and obligations of the Put Option Agreements, dated April 9, 2014, among DSHC and each of the Series E Purchasers were amended. Among other things, the definition of a “Put Trigger Event” was expanded to include the failure of the Company to pay for the Purchased Shares under the additional put right upon an RNP Change of Control described above. In addition, the number of common units of RNP securing the obligations of DSHC under the A&R Put Option Agreements was increased to 9,453,314 common units.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Note 16 — Income Taxes
	For the three months ended March 31, 2015, the Company recorded an income tax expense of $1.7 million, which is comprised of $1.7 million of income tax expense for Rentech and $0.04 million of income tax expense for RNP. The Company’s effective income tax rate (income tax expense as a percentage of income before income taxes) was 89% for the three months ended March 31, 2015. The differences between the United States federal statutory rate of 35% and the effective rate were primarily attributable to differences between GAAP income and income reported on tax returns, outside basis difference in foreign subsidiaries, impact of foreign earnings and impact of state taxes. The Company has considered results of operations and concluded that it is more likely than not that the deferred tax assets will not be realized.

Segment_Information

Segment Information	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Information	Note 17 — Segment Information
	The Company operates in five business segments, as described below. NEWP’s operations are included only from the closing date of the NEWP Acquisition, which was May 1, 2014. Allegheny’s operations are included only from the closing date of the Allegheny Acquisition, which was January 23, 2015. Results of the energy technologies segment are accounted for as discontinued operations for all periods presented. The Company’s five business segments are:
		•		East Dubuque — The operations of the East Dubuque Facility, which produces primarily ammonia and urea ammonium nitrate solution (“UAN”).
		•		Pasadena — The operations of the Pasadena Facility, which produces primarily ammonium sulfate.
		•		Fulghum Fibres — The operations of Fulghum Fibres, Inc. (“Fulghum”), which provides wood yard operations services and wood fibre processing services, sells wood chips to the pulp, paper and packaging industry, and owns and manages forestland and sells bark to industrial consumers in South America.
		•		Wood Pellets: Industrial — This segment includes wood pellet projects owned by the Company, currently the Atikokan Project and Wawa Project, and other wood pellet development activities. The wood pellet development activities represent the Company’s personnel costs for employees dedicated to the wood pellet business infrastructure and administration costs, corporate allocations, and other third party costs.
		•		Wood Pellets: NEWP — The operations of NEWP, which produces wood pellets for the residential and commercial heating markets. The segment also includes Allegheny’s operations.
	The Company’s reportable operating segments have been determined in accordance with the Company’s internal management structure, which is organized based on operating activities. The Company evaluates performance based upon several factors, of which the primary financial measure is segment operating income.
			For the Three Months
			Ended March 31,
			2015			2014
			(in thousands)
	Revenues
	East Dubuque		$	36,752		$	28,491
	Pasadena			32,422			27,789
	Fulghum Fibres			22,654			26,039	(1)
	Wood Pellets: Industrial			1,664			—
	Wood Pellets: NEWP			12,118			—
	Total revenues		$	105,610		$	82,319
	Gross profit (loss)
	East Dubuque		$	17,441		$	12,398
	Pasadena			1,342			1,366
	Fulghum Fibres			3,707			4,131
	Wood Pellets: Industrial			(404	)		—
	Wood Pellets: NEWP			2,223			—
	Total gross profit		$	24,309		$	17,895
	Selling, general and administrative expenses
	East Dubuque		$	1,346		$	1,133
	Pasadena			796			1,829
	Fulghum Fibres			1,682			1,401
	Wood Pellets: Industrial			3,919			2,068
	Wood Pellets: NEWP			704			—
	Total segment selling, general and administrative expenses		$	8,447		$	6,431
	Depreciation and amortization
	East Dubuque		$	69		$	37
	Pasadena			360			296
	Fulghum Fibres			981			(809	)
	Wood Pellets: Industrial			43			19
	Wood Pellets: NEWP			278			—
	Total segment depreciation and amortization recorded in operating expenses			1,731			(457	)
	East Dubuque		$	3,239		$	2,205
	Pasadena			1,475			766
	Fulghum Fibres			2,020			1,794
	Wood Pellets: Industrial			437			—
	Wood Pellets: NEWP			778			—
	Total depreciation and amortization recorded in cost of sales			7,949			4,765
	Total segment depreciation and amortization		$	9,680		$	4,308
	Other operating income
	East Dubuque		$	(4	)	$	(6	)
	Pasadena			—			—
	Fulghum Fibres			—			—
	Wood Pellets: Industrial			—			(342	)
	Wood Pellets: NEWP			—			—
	Total segment other operating income		$	(4	)	$	(348	)
	Operating income (loss)
	East Dubuque		$	16,030		$	11,234
	Pasadena			186			(759	)
	Fulghum Fibres			1,043			3,539
	Wood Pellets: Industrial			(4,367	)		(1,745	)
	Wood Pellets: NEWP			1,241			—
	Total segment operating income		$	14,133		$	12,269
			For the Three Months
			Ended March 31,
			2015			2014
		(in thousands)
Interest expense
East Dubuque		$	19		$	22
Pasadena			—			—
Fulghum Fibres			539			537
Wood Pellets: Industrial			116			1
Wood Pellets: NEWP			140			—
Total segment interest expense		$	814		$	560
Net income (loss)
East Dubuque		$	16,022		$	11,209
Pasadena			163			(786	)
Fulghum Fibres			(1,107	)		1,654
Wood Pellets: Industrial			(4,664	)		(1,644	)
Wood Pellets: NEWP			1,142			—
Total segment net income		$	11,556		$	10,433
Reconciliation of segment net income to consolidated net income (loss):
Segment net income		$	11,556		$	10,433
RNP — partnership and unallocated expenses recorded as selling, general and administrative expenses			(2,194	)		(2,316	)
RNP — partnership and unallocated expenses recorded as other expense			(29	)		—
RNP — unallocated interest expense and loss on interest rate swaps			(5,009	)		(4,982	)
Corporate and unallocated expenses recorded as selling, general and administrative expenses			(3,863	)		(6,825	)
Corporate and unallocated depreciation and amortization expense			(143	)		(133	)
Corporate and unallocated income recorded as other income			4			8
Corporate and unallocated interest expense			(94	)		(304	)
Corporate income tax expense			(35	)		(4	)
Loss from discontinued operations, net of tax			(147	)		(1,471	)
Consolidated net income (loss)		$	46		$	(5,594	)
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
Total assets
East Dubuque		$	194,591		$	186,508
Pasadena			197,104			193,737
Fulghum Fibres			197,591			197,418
Wood Pellets: Industrial			151,099			149,021
Wood Pellets: NEWP			65,304			56,134
Total segment assets		$	805,689		$	782,818
Reconciliation of segment total assets to consolidated total assets:
Segment total assets		$	805,689		$	782,818
RNP — partnership and other			40,507			34,071
Corporate and other			12,102			9,279
Discontinued operations			1,787			1,982
Consolidated total assets		$	860,085		$	828,150
		For the Three Months Ended
		March 31,
		2015			2014
		(in thousands)
Capital expenditures
East Dubuque		$	6,973		$	5,677
Pasadena			3,390			11,645
RNP — partnership and other			—			—
Fulghum Fibres			5,293			3,695
Wood Pellets: Industrial			13,858			17,731
Wood Pellets: NEWP			402			—
Corporate and other			155			159
Discontinued operations			—			—
Total capital expenditures		$	30,071		$	38,907
The Company’s revenues by geographic area, based on where the customer takes title to the product, were as follows:
		For the Three Months
		Ended March 31,
		2015			2014
		(in thousands)
United States		$	94,813		$	70,479
Canada			1,664			—
Other			9,133			11,840	(1)
Total revenues		$	105,610		$	82,319
The following table sets forth assets by geographic area:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
United States		$	664,638		$	637,271
Canada			151,128			149,021
Other			44,319			41,858
Total assets		$	860,085		$	828,150
-1	Previously reported amount for Fulghum Fibres’ revenues was $28,551 and revenues by geographic area - other was $14,352. Reduction to both of $2,512 is described in Note 2 — Revision of Previously Reported Revenues and Cost of Sales.

Net_Loss_Per_Common_Share_Allo

Net Loss Per Common Share Allocated to Rentech	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Net Loss Per Common Share Allocated to Rentech	Note 18 — Net Loss Per Common Share Allocated to Rentech
	Basic loss per common share allocated to Rentech is calculated by dividing net loss allocated to Rentech by the weighted average number of common shares outstanding for the period. Diluted net loss per common share allocated to Rentech is calculated by dividing net loss allocated to Rentech by the weighted average number of common shares outstanding plus the dilutive effect, calculated using (i) the “treasury stock” method for the unvested restricted stock units, outstanding stock options and warrants and (ii) the “if converted” method for the preferred stock if their inclusion would not have been anti-dilutive.
		For the Three Months
		Ended March 31,
		2015			2014
		(in thousands, except for per
		share data)
	Numerator:
	Loss from continuing operations attributable to Rentech common shareholders	$	(4,802	)	$	(5,517	)
	Less: Income from continuing operations allocated to participating securities		—			—
	Loss from continuing operations allocated to common shareholders	$	(4,802	)	$	(5,517	)
	Numerator:
	Loss from discontinued operations attributable to Rentech common shareholders	$	(147	)	$	(1,471	)
	Less: Income from discontinued operations allocated to participating securities		—			—
	Loss from discontinued operations allocated to common shareholders	$	(147	)	$	(1,471	)
	Numerator:
	Net loss attributable to Rentech common shareholders	$	(4,949	)	$	(6,988	)
	Less: Income allocated to participating securities		—			—
	Net loss allocated to common shareholders	$	(4,949	)	$	(6,988	)
	Denominator:
	Weighted average common shares outstanding		229,362			227,529
	Effect of dilutive securities:
	Preferred stock		—			—
	Warrants		—			—
	Common stock options		—			—
	Restricted stock		—			—
	Diluted shares outstanding		229,362			227,529
	Continuing operations	$	(0.02	)	$	(0.02	)
	Discontinued operations	$	0		$	(0.01	)
	Basic net loss per common share	$	(0.02	)	$	(0.03	)
	Continuing operations	$	(0.02	)	$	(0.02	)
	Discontinued operations	$	0		$	(0.01	)
	Diluted net loss per common share	$	(0.02	)	$	(0.03	)
	For the three months ended March 31, 2015, 60.5 million shares of Common Stock issuable pursuant to stock options, stock warrants, restricted stock units and preferred stock were excluded from the calculation of diluted loss per share because their inclusion would have been anti-dilutive. For the three months ended March 31, 2014, 16.0 million shares of Common Stock issuable pursuant to stock options, stock warrants, and restricted stock units were excluded from the calculation of diluted loss per share because their inclusion would have been anti-dilutive.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Note 19 — Subsequent Events
	A&R GSO Credit Agreement
	In April 2015, the Company borrowed an additional $7.5 million under the A&R GSO Credit Agreement.
	Distributions
	On May 11, 2015, RNP announced a cash distribution to its common unitholders for the first quarter of 2015 of $0.36 per unit, which will result in total distributions of $14.1 million, including payments to phantom unitholders. The Company will receive a distribution of $8.4 million, representing its share of distributions based on its ownership of common units. The cash distribution will be paid on May 29, 2015 to unitholders of record at the close of business on May 22, 2015.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2015
Basis of presentation	The accompanying unaudited consolidated financial statements of Rentech, Inc. (“Rentech”) and its consolidated subsidiaries (collectively, the “Company”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in compliance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Neither authority requires all of the information and footnotes required by GAAP for complete financial statements. Accordingly, the accompanying financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, considered necessary for a fair statement of the Company’s financial position as of March 31, 2015, and the results of operations and cash flows for the periods presented. The accompanying consolidated financial statements include the accounts of Rentech, its wholly owned subsidiaries and all subsidiaries in which Rentech directly or indirectly owns a controlling financial interest. All significant intercompany accounts and transactions have been eliminated in consolidation. Operating results for the three months ended March 31, 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 or any other reporting period. The information included in this Form 10-Q should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 filed with the Securities and Exchange Commission (the “SEC”) on March 16, 2015 (the “Annual Report”).
	The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Fair value measurement	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants and is classified in one of the following three categories:
		•	Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date.
		•	Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data.
		•	Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
	Fair values of cash, receivables, deposits, other current assets, accounts payable, accrued liabilities and other current liabilities were assumed to approximate carrying value since they are short term and can be settled on demand.
Earnings Per share	Basic loss per common share allocated to Rentech is calculated by dividing net loss allocated to Rentech by the weighted average number of common shares outstanding for the period. Diluted net loss per common share allocated to Rentech is calculated by dividing net loss allocated to Rentech by the weighted average number of common shares outstanding plus the dilutive effect, calculated using (i) the “treasury stock” method for the unvested restricted stock units, outstanding stock options and warrants and (ii) the “if converted” method for the preferred stock if their inclusion would not have been anti-dilutive.
Wood Pellets NEWP [Member]
Business combinations	This business combination was accounted for using the acquisition method of accounting, which requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date.
Allegheny [Member]
Business combinations	The acquisition is considered a business combination and has been accounted for using the acquisition method of accounting, which requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date.

Revision_of_Previously_Reporte1

Revision of Previously Reported Revenues and Cost of Sales (Tables)	3 Months Ended
	Mar. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Schedule of Revision of Previously Reported Revenues and Cost of Sales
		For the Years Ended
		December 31,
		2014			2013
		(in thousands)
	As Reported:
	Revenues	$	472,661		$	374,349
	Product sales		400,282			322,022
	Service revenues		70,317			49,822
	Cost of sales		392,987			290,963
	Product cost of sales		335,544			252,741
	Service cost of sales		57,443			38,222
	Effect of Revisions:
	Revenues	$	(7,101	)	$	(4,690	)
	Product sales		(7,101	)		(3,060	)
	Service revenues		—			(1,630	)
	Cost of sales		(7,101	)		(4,690	)
	Product cost of sales		(7,101	)		(3,060	)
	Service cost of sales		—			(1,630	)
	As Revised:
	Revenues	$	465,560		$	369,659
	Product sales		393,181			318,962
	Service revenues		70,317			48,192
	Cost of sales		385,886			286,273
	Product cost of sales		328,443			249,681
	Service cost of sales		57,443			36,592
		For the Three Months Ended
		March 31,			June 30,						September 30,						December 31,
		2014			2014			2013			2014			2013			2014			2013
		(in thousands)
	As Reported:
	Revenues	$	84,831		$	139,890		$	120,061		$	125,304		$	115,657		$	122,636		$	79,067
	Product sales		65,345			123,007			107,545			106,802			96,621			105,128			59,132
	Service revenues		18,962			16,425			11,732			17,955			18,608			16,975			19,482
	Cost of sales		66,936			108,451			77,788			112,335			94,513			105,265			81,817
	Product cost of sales		51,684			94,455			68,254			97,880			80,272			91,525			67,370
	Service cost of sales		15,252			13,996			9,534			14,455			14,241			13,740			14,447
	Effect of Revisions:
	Revenues	$	(2,512	)	$	(690	)	$	(773	)	$	(3,132	)	$	(1,511	)	$	(767	)	$	(2,406	)
	Product sales		(1,797	)		(1,405	)		(488	)		(3,132	)		(945	)		(767	)		(1,627	)
	Service revenues		(715	)		715			(285	)		—			(566	)		—			(779	)
	Cost of sales		(2,512	)		(690	)		(773	)		(3,132	)		(1,511	)		(767	)		(2,406	)
	Product cost of sales		(1,797	)		(1,405	)		(488	)		(3,132	)		(945	)		(767	)		(1,627	)
	Service cost of sales		(715	)		715			(285	)		—			(566	)		—			(779	)
	As Revised:
	Revenues	$	82,319		$	139,200		$	119,288		$	122,172		$	114,146		$	121,869		$	76,661
	Product sales		63,548			121,602			107,057			103,670			95,676			104,361			57,505
	Service revenues		18,247			17,140			11,447			17,955			18,042			16,975			18,703
	Cost of sales		64,424			107,761			77,015			109,203			93,002			104,498			79,411
	Product cost of sales		49,887			93,050			67,766			94,748			79,327			90,758			65,743
	Service cost of sales		14,537			14,711			9,249			14,455			13,675			13,740			13,668
		For the Six Months Ended						For the Nine Months Ended
		June 30,						September 30,
		2014			2013			2014			2013
		(in thousands)						(in thousands)
	As Reported:
	Revenues	$	224,721		$	179,625		$	350,025		$	295,282
	Product sales		188,352			166,269			295,154			262,890
	Service revenues		35,387			11,732			53,342			30,340
	Cost of sales		175,387			114,633			287,722			209,146
	Product cost of sales		146,139			105,099			244,019			185,371
	Service cost of sales		29,248			9,534			43,703			23,775
	Effect of Revisions:
	Revenues	$	(3,202	)	$	(773	)	$	(6,334	)	$	(2,284	)
Product sales		(3,202	)		(488	)		(6,334	)		(1,433	)
Service revenues		—			(285	)		—			(851	)
Cost of sales		(3,202	)		(773	)		(6,334	)		(2,284	)
Product cost of sales		(3,202	)		(488	)		(6,334	)		(1,433	)
Service cost of sales		—			(285	)		—			(851	)
As Revised:
Revenues	$	221,519		$	178,852		$	343,691		$	292,998
Product sales		185,150			165,781			288,820			261,457
Service revenues		35,387			11,447			53,342			29,489
Cost of sales		172,185			113,860			281,388			206,862
Product cost of sales		142,937			104,611			237,685			183,938
Service cost of sales		29,248			9,249			43,703			22,924

Acquisition_Tables

Acquisition (Tables)	3 Months Ended
	Mar. 31, 2015
Wood Pellets NEWP [Member]
Purchase Price Allocation	The Company’s final purchase price allocation is as follows (amounts in thousands):
	Cash		$	3,852
	Accounts receivable			2,925
	Inventories			2,239
	Prepaid expenses and other current assets			439
	Property, plant and equipment			30,625
	Intangible assets (trade name - $5,000, customer relationships - $1,900, and non-compete agreements - $200)			7,100
	Goodwill			8,461
	Accounts payable			(1,641	)
	Accrued liabilities			(442	)
	Customer deposits			(882	)
	Loans			(12,600	)
	Interest rate swaps			(802	)
	Total preliminary purchase price(2)		$	39,274
	-2	The difference between the final purchase price of $40.4 million and the preliminary purchase price of $39.3 million is the $1.1 million of additional earn-out consideration, which was recorded subsequent to the closing date of the NEWP Acquisition in the consolidated statement of operations.
Allegheny [Member]
Purchase Price Allocation	The Company’s preliminary purchase price allocation is as follows (amounts in thousands):
	Inventories		$	214
	Property, plant and equipment			3,937
	Construction in progress			28
	Intangible assets (customer relationships - $800 and trade name - $400)			1,200
	Goodwill			1,862
	Accrued liabilities			(27	)
	Total purchase price		$	7,214
As Reported [Member] | Wood Pellets NEWP [Member]
Purchase Price	The final purchase price recognized in our financial statements consisted of the following (amounts in thousands):
	Cash		$	35,434
	Earn-out consideration(1)			5,000
	Total final purchase price		$	40,434
	-1	As of December 31, 2014, the earn-out consideration of $5.0 million was earned, and during the three months ended March 31, 2015, it was paid.

Pro_Forma_Information_Tables

Pro Forma Information (Tables)	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
Pro Forma Information	The unaudited pro forma information has been prepared as if the Allegheny Acquisition and the NEWP Acquisition had taken place on January 1, 2014. The unaudited pro forma information is not necessarily indicative of the results that the Company would have achieved had the transactions actually taken place on January 1, 2014, and the unaudited pro forma information does not purport to be indicative of future financial operating results.
		For the Three Months Ended March 31, 2015
		As Reported			Pro Forma		Pro Forma
					Adjustments
		(in thousands)
	Revenues	$	105,610		$	389	$	105,999
	Net income	$	46		$	155	$	201
	Net income (loss) attributable to Rentech	$	(4,949	)	$	155	$	(4,794	)
	Basic and diluted net income (loss) from continuing operations per common share allocated to Rentech	$	(0.02	)	$	0	$	(0.02	)
		For the Three Months Ended March 31, 2014
		As Reported			Pro Forma		Pro Forma
					Adjustments
		(in thousands)
	Revenues	$	82,319		$	12,601	$	94,920
	Net income (loss)	$	(5,594	)	$	962	$	(4,632	)
	Net income (loss) attributable to Rentech	$	(6,988	)	$	962	$	(6,026	)
	Basic and diluted net income (loss) from continuing operations per common share allocated to Rentech	$	(0.02	)	$	0	$	(0.02	)

Discontinued_Operations_Tables

Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The following table summarizes the components of assets and liabilities of discontinued operations.
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Prepaid expenses and other current assets	$	110		$	305
	Total current assets	$	110		$	305
	Property held for sale	$	1,677		$	1,677
	Total other assets	$	1,677		$	1,677
	Total assets	$	1,787		$	1,982
	Accounts payable	$	32		$	144
	Accrued payroll and benefits		223			559
	Accrued liabilities		264			1,008
	Other		687			—
	Total liabilities	$	1,206		$	1,711
	The following table summarizes the results of discontinued operations.
		For the Three Months Ended
		March 31,
		2015			2014
		(in thousands)
	Revenues	$	56		$	156
	Operating loss	$	(147	)	$	(1,498	)
	Loss from discontinued operations, net of tax	$	(147	)	$	(1,471	)

Fair_Value_Tables

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Disclosure	The following table presents the financial instruments that were accounted for at fair value by level as of March 31, 2015 and December 31, 2014.
		Level 1			Level 2			Level 3
		(in thousands)
	Liabilities
	Earn-out consideration — March 31, 2015	$	—		$	—		$	1,184
	Earn-out consideration — December 31, 2014	$	—		$	—		$	1,295
Fair Value and Carrying Value of Borrowings and Interest Rate Swaps	The following table presents the fair value and carrying value of the Company’s borrowings as of March 31, 2015.
		Fair Value									Carrying Value
		(in thousands)
		Level 1			Level 2			Level 3
	Liabilities
	RNP Notes	$	311,002		$	—		$	—		$	320,000
	Fulghum debt		—			49,333			—			53,020
	NEWP debt		—			18,357			—			18,607
	A&R GSO Credit Agreement		—			75,000			—			73,700
	GE Credit Agreement		—			19,000			—			19,000
	The following table presents the fair value and carrying value of the Company’s borrowings as of December 31, 2014.
		Fair Value									Carrying Value
		(in thousands)
		Level 1			Level 2			Level 3
	Liabilities
	RNP Notes	$	310,202		$	—		$	—		$	320,000
	Fulghum debt		—			53,192			—			54,771
	NEWP debt		—			10,968			—			11,265
	A&R GSO Credit Agreement		—			50,000			—			49,142
	GE Credit Agreement		—			15,000			—			15,000
Reconciliation of the Change in the Carrying Value of Earn-out Consideration	A reconciliation of the change in the carrying value of the earn-out consideration during 2015 is as follows:
		Atikokan			NEWP			Total
		(in thousands)
	Balance at December 31, 2014	$	1,295		$	5,000		$	6,295
	Add: Unrealized gain on foreign currency translation		(111	)		—			(111	)
	Less: Earn-out consideration payment		—			(5,000	)		(5,000	)
	Balance at March 31, 2015	$	1,184		$	—		$	1,184
	A reconciliation of the change in the carrying value of the earn-out consideration during 2014 is as follows:
		Atikokan
		(in thousands)
	Balance at December 31, 2013	$	1,544
	Add: Unrealized gain		(58	)
	Balance at March 31, 2014	$	1,486

Derivative_Instruments_Tables

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net Gain (Loss) on Interest Rate Swaps	Net gain (loss) on interest rate swaps:
		For the Three
		Months
		Ended March 31,
		2015
	Realized loss	$	—
	Unrealized gain (loss)		24
	Total net gain (loss) on interest rate swaps	$	24
Forward Natural Gas Contracts and Interest Rate Swaps Recorded in Accrued Liabilities and Other Liabilities	The forward natural gas contracts are recorded in accrued liabilities on the consolidated balance sheets.
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Forward natural gas contracts recorded in current liabilities:
	Gross amounts recognized	$	1,382		$	3,955
	Gross amounts offset in consolidated balance sheets		(7	)		—
	Net amounts presented in the consolidated balance sheets	$	1,375		$	3,955
	The interest rate swaps are recorded in other liabilities on the consolidated balance sheets.
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Interest rate swaps recorded in current liabilities:
	Gross amounts recognized	$	629		$	653
	Gross amounts offset in consolidated balance sheets		—			—
	Net amounts presented in the consolidated balance sheets	$	629		$	653
Schedule of Financial Instruments at Fair Value	The following table presents the financial instruments that were accounted for at fair value by level as of March 31, 2015:
		Level 1			Level 2		Level 3
		(in thousands)
	Liabilities
	Forward gas contracts	$	—		$	1,375	$	—
	Interest rate swaps		—			629		—
	The following table presents the financial instruments that were accounted for at fair value by level as of December 31, 2014:
		Level 1			Level 2		Level 3
		(in thousands)
	Liabilities
	Forward gas contracts	$	—		$	3,955	$	—
	Interest rate swaps		—			653		—

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories consisted of the following:
		As of
		March 31,		December 31,
		2015		2014
		(in thousands)
	Finished goods	$	39,157	$	26,669
	Raw materials		13,899		11,226
	Other		238		190
	Total inventory	$	53,294	$	38,085

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, plant and equipment consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Land and land improvements	$	28,072		$	28,042
	Buildings and building improvements		46,486			45,516
	Machinery and equipment		490,249			406,489
	Furniture, fixtures and office equipment		1,782			1,610
	Computer equipment and computer software		10,384			8,748
	Vehicles		7,149			5,893
	Leasehold improvements		2,454			2,405
	Other		1,453			1,453
			588,029			500,156
	Less: Accumulated depreciation		(117,355	)		(107,705	)
	Total property, plant and equipment, net	$	470,674		$	392,451
Construction in Progress	Construction in progress consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	East Dubuque Facility	$	14,790		$	15,010
	Pasadena Facility		207			32,747
	Fulghum Fibres		2,135			7,197
	Atikokan Project		—			36,931
	Wawa Project		66,944			65,232
	Construction under QS Construction Facility		25,698			21,712
	Other		766			594
	Total construction in progress	$	110,540		$	179,423

Goodwill_Tables

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Reconciliation of Change in Carrying Value of Goodwill	A reconciliation of the change in the carrying value of goodwill is as follows:
		Fulghum		NEWP		Total
		(in thousands)
	Balance at December 31, 2014	$	29,932	$	8,461	$	38,393
	Add: Allegheny Acquisition		—		1,862		1,862
	Balance at March 31, 2015	$	29,932	$	10,323	$	40,255

Debt_Tables

Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Summary of Total Debt	As of March 31, 2015, the Company was in compliance with its debt covenants. Total debt consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	RNP Notes	$	320,000		$	320,000
	QS Construction Facility		22,788			18,679
	Fulghum debt		51,592			53,179
	A&R GSO Credit Agreement		75,000			50,000
	NEWP debt		18,290			10,913
	GE Credit Agreement		19,000			15,000
	Total debt	$	506,670		$	467,771
	Plus: Unamortized net premium		446			1,085
	Less: Current portion		(18,131	)		(17,260	)
	Less: Current portion unamortized premium		(521	)		(524	)
	Long-term debt	$	488,464		$	451,072

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments for Natural Gas Purchases	Commitments for natural gas purchases consist of the following:
		As of
		March 31,		December 31,
		2015		2014
		(in thousands, except weighted
		average rate)
	MMBtus under fixed-price contracts		3,505		3,188
	MMBtus under index-price contracts		—		540
	Total MMBtus under contracts		3,505		3,728
	Commitments to purchase natural gas	$	10,508	$	15,568
	Weighted average rate per MMBtu based on the fixed rates and the indexes applicable to each contract	$	3	$	4.18

Preferred_Stock_Tables

Preferred Stock (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule of Mezzanine Equity	Mezzanine equity consisted of the following:
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
	Original issue price of 2014 Preferred Stock	$	100,000		$	100,000
	Less: Issuance costs		(3,020	)		(3,144	)
	Less: Unamortized discount		(1,725	)		(1,796	)
	Total mezzanine equity	$	95,255		$	95,060

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Information	The Company’s reportable operating segments have been determined in accordance with the Company’s internal management structure, which is organized based on operating activities. The Company evaluates performance based upon several factors, of which the primary financial measure is segment operating income.
			For the Three Months
			Ended March 31,
			2015			2014
			(in thousands)
	Revenues
	East Dubuque		$	36,752		$	28,491
	Pasadena			32,422			27,789
	Fulghum Fibres			22,654			26,039	(1)
	Wood Pellets: Industrial			1,664			—
	Wood Pellets: NEWP			12,118			—
	Total revenues		$	105,610		$	82,319
	Gross profit (loss)
	East Dubuque		$	17,441		$	12,398
	Pasadena			1,342			1,366
	Fulghum Fibres			3,707			4,131
	Wood Pellets: Industrial			(404	)		—
	Wood Pellets: NEWP			2,223			—
	Total gross profit		$	24,309		$	17,895
	Selling, general and administrative expenses
	East Dubuque		$	1,346		$	1,133
	Pasadena			796			1,829
	Fulghum Fibres			1,682			1,401
	Wood Pellets: Industrial			3,919			2,068
	Wood Pellets: NEWP			704			—
	Total segment selling, general and administrative expenses		$	8,447		$	6,431
	Depreciation and amortization
	East Dubuque		$	69		$	37
	Pasadena			360			296
	Fulghum Fibres			981			(809	)
	Wood Pellets: Industrial			43			19
	Wood Pellets: NEWP			278			—
	Total segment depreciation and amortization recorded in operating expenses			1,731			(457	)
	East Dubuque		$	3,239		$	2,205
	Pasadena			1,475			766
	Fulghum Fibres			2,020			1,794
	Wood Pellets: Industrial			437			—
	Wood Pellets: NEWP			778			—
	Total depreciation and amortization recorded in cost of sales			7,949			4,765
	Total segment depreciation and amortization		$	9,680		$	4,308
	Other operating income
	East Dubuque		$	(4	)	$	(6	)
	Pasadena			—			—
	Fulghum Fibres			—			—
	Wood Pellets: Industrial			—			(342	)
	Wood Pellets: NEWP			—			—
	Total segment other operating income		$	(4	)	$	(348	)
	Operating income (loss)
	East Dubuque		$	16,030		$	11,234
	Pasadena			186			(759	)
	Fulghum Fibres			1,043			3,539
	Wood Pellets: Industrial			(4,367	)		(1,745	)
	Wood Pellets: NEWP			1,241			—
	Total segment operating income		$	14,133		$	12,269
			For the Three Months
			Ended March 31,
			2015			2014
			(in thousands)
	Interest expense
	East Dubuque		$	19		$	22
	Pasadena			—			—
	Fulghum Fibres			539			537
	Wood Pellets: Industrial			116			1
	Wood Pellets: NEWP			140			—
Total segment interest expense		$	814		$	560
Net income (loss)
East Dubuque		$	16,022		$	11,209
Pasadena			163			(786	)
Fulghum Fibres			(1,107	)		1,654
Wood Pellets: Industrial			(4,664	)		(1,644	)
Wood Pellets: NEWP			1,142			—
Total segment net income		$	11,556		$	10,433
Reconciliation of segment net income to consolidated net income (loss):
Segment net income		$	11,556		$	10,433
RNP — partnership and unallocated expenses recorded as selling, general and administrative expenses			(2,194	)		(2,316	)
RNP — partnership and unallocated expenses recorded as other expense			(29	)		—
RNP — unallocated interest expense and loss on interest rate swaps			(5,009	)		(4,982	)
Corporate and unallocated expenses recorded as selling, general and administrative expenses			(3,863	)		(6,825	)
Corporate and unallocated depreciation and amortization expense			(143	)		(133	)
Corporate and unallocated income recorded as other income			4			8
Corporate and unallocated interest expense			(94	)		(304	)
Corporate income tax expense			(35	)		(4	)
Loss from discontinued operations, net of tax			(147	)		(1,471	)
Consolidated net income (loss)		$	46		$	(5,594	)
		As of
		March 31,			December 31,
		2015			2014
		(in thousands)
Total assets
East Dubuque		$	194,591		$	186,508
Pasadena			197,104			193,737
Fulghum Fibres			197,591			197,418
Wood Pellets: Industrial			151,099			149,021
Wood Pellets: NEWP			65,304			56,134
Total segment assets		$	805,689		$	782,818
Reconciliation of segment total assets to consolidated total assets:
Segment total assets		$	805,689		$	782,818
RNP — partnership and other			40,507			34,071
Corporate and other			12,102			9,279
Discontinued operations			1,787			1,982
Consolidated total assets		$	860,085		$	828,150
		For the Three Months Ended
		March 31,
		2015			2014
		(in thousands)
Capital expenditures
East Dubuque		$	6,973		$	5,677
Pasadena			3,390			11,645
RNP — partnership and other			—			—
Fulghum Fibres			5,293			3,695
Wood Pellets: Industrial			13,858			17,731
Wood Pellets: NEWP			402			—
Corporate and other			155			159
Discontinued operations			—			—
Total capital expenditures		$	30,071		$	38,907
Summary of Revenues by Geographic Area	The Company’s revenues by geographic area, based on where the customer takes title to the product, were as follows:
			For the Three Months
			Ended March 31,
			2015			2014
			(in thousands)
	United States		$	94,813		$	70,479
	Canada			1,664			—
	Other			9,133			11,840	(1)
	Total revenues		$	105,610		$	82,319
	-1	Previously reported amount for Fulghum Fibres’ revenues was $28,551 and revenues by geographic area - other was $14,352. Reduction to both of $2,512 is described in Note 2 — Revision of Previously Reported Revenues and Cost of Sales.
Summary of Assets by Geographic Area	The following table sets forth assets by geographic area:
			As of
			March 31,			December 31,
			2015			2014
			(in thousands)
	United States		$	664,638		$	637,271
	Canada			151,128			149,021
	Other			44,319			41,858
	Total assets		$	860,085		$	828,150

Net_Loss_Per_Common_Share_Allo1

Net Loss Per Common Share Allocated to Rentech (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted
		For the Three Months
		Ended March 31,
		2015			2014
		(in thousands, except for per
		share data)
	Numerator:
	Loss from continuing operations attributable to Rentech common shareholders	$	(4,802	)	$	(5,517	)
	Less: Income from continuing operations allocated to participating securities		—			—
	Loss from continuing operations allocated to common shareholders	$	(4,802	)	$	(5,517	)
	Numerator:
	Loss from discontinued operations attributable to Rentech common shareholders	$	(147	)	$	(1,471	)
	Less: Income from discontinued operations allocated to participating securities		—			—
	Loss from discontinued operations allocated to common shareholders	$	(147	)	$	(1,471	)
	Numerator:
	Net loss attributable to Rentech common shareholders	$	(4,949	)	$	(6,988	)
	Less: Income allocated to participating securities		—			—
	Net loss allocated to common shareholders	$	(4,949	)	$	(6,988	)
	Denominator:
	Weighted average common shares outstanding		229,362			227,529
	Effect of dilutive securities:
	Preferred stock		—			—
	Warrants		—			—
	Common stock options		—			—
	Restricted stock		—			—
	Diluted shares outstanding		229,362			227,529
	Continuing operations	$	(0.02	)	$	(0.02	)
	Discontinued operations	$	0		$	(0.01	)
	Basic net loss per common share	$	(0.02	)	$	(0.03	)
	Continuing operations	$	(0.02	)	$	(0.02	)
	Discontinued operations	$	0		$	(0.01	)
	Diluted net loss per common share	$	(0.02	)	$	(0.03	)

Basis_of_Presentation_Addition

Basis of Presentation - Additional Information (Detail) (RNP [Member])	Mar. 31, 2015
In Millions, unless otherwise specified
RNP [Member]
Subsidiary, Sale of Stock [Line Items]
Number of unpledged common units owned	3.1

Revision_of_Previously_Reporte2

Revision of Previously Reported Revenues and Cost of Sales - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Accounting Changes and Error Corrections [Abstract]
Increase (decrease) in revenue and cost of goods sold	$2,512	$7,100	$4,700

Revision_of_Previously_Reporte3

Revision of Previously Reported Revenues and Cost of Sales - Schedule of Revision of Previously Reported Revenues and Cost of Sales (Detail) (USD $)	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013
Revenues	$105,610	$121,869	$122,172	$139,200	$82,319	$76,661	$114,146	$119,288	$221,519	$178,852	$343,691	$292,998	$465,560	$369,659
Product sales	88,468	104,361	103,670	121,602	63,548	57,505	95,676	107,057	185,150	165,781	288,820	261,457	393,181	318,962
Service revenues	16,603	16,975	17,955	17,140	18,247	18,703	18,042	11,447	35,387	11,447	53,342	29,489	70,317	48,192
Cost of sales	81,301	104,498	109,203	107,761	64,424	79,411	93,002	77,015	172,185	113,860	281,388	206,862	385,886	286,273
Product cost of sales	67,971	90,758	94,748	93,050	49,887	65,743	79,327	67,766	142,937	104,611	237,685	183,938	328,443	249,681
Service cost of sales	13,330	13,740	14,455	14,711	14,537	13,668	13,675	9,249	29,248	9,249	43,703	22,924	57,443	36,592
As Reported [Member]
Revenues		122,636	125,304	139,890	84,831	79,067	115,657	120,061	224,721	179,625	350,025	295,282	472,661	374,349
Product sales		105,128	106,802	123,007	65,345	59,132	96,621	107,545	188,352	166,269	295,154	262,890	400,282	322,022
Service revenues		16,975	17,955	16,425	18,962	19,482	18,608	11,732	35,387	11,732	53,342	30,340	70,317	49,822
Cost of sales		105,265	112,335	108,451	66,936	81,817	94,513	77,788	175,387	114,633	287,722	209,146	392,987	290,963
Product cost of sales		91,525	97,880	94,455	51,684	67,370	80,272	68,254	146,139	105,099	244,019	185,371	335,544	252,741
Service cost of sales		13,740	14,455	13,996	15,252	14,447	14,241	9,534	29,248	9,534	43,703	23,775	57,443	38,222
Effect of Revisions [Member]
Revenues		-767	-3,132	-690	-2,512	-2,406	-1,511	-773	-3,202	-773	-6,334	-2,284	-7,101	-4,690
Product sales		-767	-3,132	-1,405	-1,797	-1,627	-945	-488	-3,202	-488	-6,334	-1,433	-7,101	-3,060
Service revenues				715	-715	-779	-566	-285		-285		-851		-1,630
Cost of sales		-767	-3,132	-690	-2,512	-2,406	-1,511	-773	-3,202	-773	-6,334	-2,284	-7,101	-4,690
Product cost of sales		-767	-3,132	-1,405	-1,797	-1,627	-945	-488	-3,202	-488	-6,334	-1,433	-7,101	-3,060
Service cost of sales				$715	($715)	($779)	($566)	($285)		($285)		($851)		($1,630)

Allegheny_Acquisition_Addition

Allegheny Acquisition - Additional Information (Detail) (USD $)

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

0 Months Ended

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2014

Dec. 31, 2013

Jan. 23, 2015

Business Acquisition [Line Items]

Revenue

$105,610,000

$121,869,000

$122,172,000

$139,200,000

$82,319,000

$76,661,000

$114,146,000

$119,288,000

$221,519,000

$178,852,000

$343,691,000

$292,998,000

$465,560,000

$369,659,000

Gross profit

24,309,000

17,895,000

Allegheny [Member]

Business Acquisition [Line Items]

Acquired assets

7,200,000

Term loan amount

8,000,000

Term loan period

5 years

Revenue

1,200,000

Gross profit

$100,000

Allegheny [Member] | Trade Names [Member]

Business Acquisition [Line Items]

Estimated useful life

15 years

Allegheny [Member] | Customer Relationships [Member]

Business Acquisition [Line Items]

Estimated useful life

15 years

Allegheny_Acquisition_Purchase

Allegheny Acquisition - Purchase Price Allocation (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	1-May-14	Jan. 23, 2015
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Construction in progress	$110,540	$179,423
Goodwill	40,255	38,393
Total preliminary purchase price			39,274
Allegheny [Member]
Business Acquisition [Line Items]
Inventories				214
Property, plant and equipment				3,937
Construction in progress				28
Intangible assets				1,200
Goodwill				1,862
Accrued liabilities				-27
Total preliminary purchase price				$7,214

Allegheny_Acquisition_Purchase1

Allegheny Acquisition - Purchase Price Allocation (Parenthetical) (Detail) (Allegheny [Member], USD $)	Jan. 23, 2015
In Thousands, unless otherwise specified
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	$800
Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets	$400

NEWP_Acquisition_Additional_In

NEWP Acquisition - Additional Information (Detail) (Wood Pellets NEWP [Member], USD $)	0 Months Ended	3 Months Ended
	1-May-14	Mar. 31, 2015	1-May-14
Business Acquisition [Line Items]
Business acquisition date		1-May-14
Business acquisition purchase price, cash paid	$35,400,000	$35,434,000
Additional contingent consideration	$5,000,000		$5,000,000
Trade Names [Member]
Business Acquisition [Line Items]
Estimated useful life		20 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated useful life		13 years
Non-compete Agreements [Member]
Business Acquisition [Line Items]
Estimated useful life		3 years

NEWP_Acquisition_Purchase_Pric

NEWP Acquisition - Purchase Price (Detail) (Wood Pellets NEWP [Member], USD $)	0 Months Ended	3 Months Ended
In Thousands, unless otherwise specified	1-May-14	Mar. 31, 2015
Wood Pellets NEWP [Member]
Business Acquisition [Line Items]
Cash	$35,400	$35,434
Earn-out consideration		5,000
Total final purchase price	$40,400	$40,434

NEWP_Acquisition_Purchase_Pric1

NEWP Acquisition - Purchase Price (Parenthetical) (Detail) (Wood Pellets NEWP [Member], USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Wood Pellets NEWP [Member]
Business Acquisition [Line Items]
Earn-out consideration	$5,000

NEWP_Acquisition_Purchase_Pric2

NEWP Acquisition - Purchase Price Allocation (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	1-May-14	Jan. 23, 2015
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill	$40,255	$38,393
Total preliminary purchase price			39,274
Wood Pellets NEWP [Member]
Business Acquisition [Line Items]
Cash			3,852
Accounts receivable			2,925
Inventories			2,239
Prepaid expenses and other current assets			439
Property, plant and equipment			30,625
Intangible assets			7,100
Goodwill			8,461
Accounts payable			-1,641
Accrued liabilities			-442
Customer deposits			-882
Loans			-12,600	-8,000
Interest rate swaps			-802
Total preliminary purchase price			$39,300

NEWP_Acquisition_Purchase_Pric3

NEWP Acquisition - Purchase Price Allocation (Parenthetical) (Detail) (USD $)	0 Months Ended	3 Months Ended
	1-May-14	Mar. 31, 2015	1-May-14
Business Acquisition [Line Items]
Total preliminary purchase price	$39,274,000		$39,274,000
Wood Pellets NEWP [Member]
Business Acquisition [Line Items]
Total final purchase price	40,400,000	40,434,000
Total preliminary purchase price	39,300,000		39,300,000
Additional earn-out consideration	1,100,000
Wood Pellets NEWP [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets	5,000,000		5,000,000
Wood Pellets NEWP [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	1,900,000		1,900,000
Wood Pellets NEWP [Member] | Non-compete Agreements [Member]
Business Acquisition [Line Items]
Intangible assets	$200,000		$200,000

Pro_Forma_Information_Pro_Form

Pro Forma Information - Pro Forma Information (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Business Acquisition, Pro Forma Information [Abstract]
Revenues	$105,999	$94,920
Net income	201	-4,632
Net income (loss) attributable to Rentech	-4,794	-6,026
Basic and diluted net income (loss) from continuing operations per common share allocated to Rentech	($0.02)	($0.02)
As Reported [Member]
Business Acquisition, Pro Forma Information [Abstract]
Revenues	105,610	82,319
Net income	46	-5,594
Net income (loss) attributable to Rentech	-4,949	-6,988
Basic and diluted net income (loss) from continuing operations per common share allocated to Rentech	($0.02)	($0.02)
Pro Forma Adjustments [Member]
Business Acquisition, Pro Forma Information [Abstract]
Revenues	389	12,601
Net income	155	962
Net income (loss) attributable to Rentech	$155	$962
Basic and diluted net income (loss) from continuing operations per common share allocated to Rentech	$0	$0

Discontinued_Operations_Schedu

Discontinued Operations - Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Prepaid expenses and other current assets	$110		$305
Total current assets	110		305
Property held for sale	1,677		1,677
Total other assets	1,677		1,677
Total assets	1,787		1,982
Accounts payable	32		144
Accrued payroll and benefits	223		559
Accrued liabilities	264		1,008
Other	687
Total liabilities	1,206		1,711
Revenues	56	156
Operating loss	-147	-1,498
Loss from discontinued operations, net of tax	($147)	($1,471)

Fair_Value_Fair_Value_Disclosu

Fair Value - Fair Value Disclosure (Detail) (Level 3 [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Earn-out consideration - December 31, 2014	$1,184	$1,295

Fair_Value_Fair_Value_and_Carr

Fair Value - Fair Value and Carrying Value of Borrowings and Interest Rate Swaps (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Liabilities
RNP Notes	$320,000	$320,000
Fulghum [Member]
Liabilities
Fulghum debt	53,020	54,771
Wood Pellets NEWP [Member]
Liabilities
NEWP debt		11,265
NEWP debt	18,607
A&R GSO Credit Agreement [Member]
Liabilities
Credit Agreement / Revolving Loan	73,700	49,142
GE Credit Agreement [Member]
Liabilities
Credit Agreement / Revolving Loan	19,000	15,000
Level 1 [Member]
Liabilities
RNP Notes	311,002	310,202
Level 2 [Member] | Fulghum [Member]
Liabilities
Fulghum debt	49,333	53,192
Level 2 [Member] | Wood Pellets NEWP [Member]
Liabilities
NEWP debt	18,357	10,968
Level 2 [Member] | A&R GSO Credit Agreement [Member]
Liabilities
Credit Agreement / Revolving Loan	75,000	50,000
Level 2 [Member] | GE Credit Agreement [Member]
Liabilities
Credit Agreement / Revolving Loan	$19,000	$15,000

Fair_Value_Additional_Informat

Fair Value - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Earn-out consideration, Carrying Value	$1,184,000	$6,295,000
Senior secured note, Amount	320,000,000	320,000,000
Senior secured note, Percentage	6.50%
Atikokan Project [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Earn-out consideration, Carrying Value	1,184,000	1,295,000	1,486,000	1,544,000
Number of years to determine fair value of earn-out consideration	10 years
Loan provided to sellers	700,000
Increase or decrease in EBITDA	1,000,000
Increase or decrease in earn-out consideration	$100,000

Fair_Value_Reconciliation_of_t

Fair Value - Reconciliation of the Change in the Carrying Value of Earn-out Consideration (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$6,295
Add: Unrealized gain on foreign currency translation	-111
Less: Earn-out consideration payment	-5,000
Ending Balance	1,184
Atikokan Project [Member]
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	1,295	1,544
Add: Unrealized gain on foreign currency translation	-111
Add: Unrealized (gain) loss		-58
Ending Balance	1,184	1,486
Wood Pellets NEWP [Member]
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	5,000
Less: Earn-out consideration payment	($5,000)

Derivative_Instruments_Additio

Derivative Instruments - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gain (loss) on derivatives	$2,604,000
Interest Rate Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gain (loss) on derivatives	-600,000	-700,000
Mortgage Loans on Real Estate [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative fixed interest rate	7.95%
Industrial Revenue Bond [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative fixed interest rate	5.29%
Industrial Revenue Bond [Member] | Mortgage Loans on Real Estate [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of derivative contracts	3
Other Industrial Revenue Bond [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative fixed interest rate	5.05%
Forward Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gain (loss) on derivatives	$2,600,000		$0

Derivative_Instruments_Net_Gai

Derivative Instruments - Net Gain (Loss) on Interest Rate Swaps (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Unrealized gain (loss)	($2,604,000)
Interest Rate Swaps [Member]
Derivative [Line Items]
Unrealized gain (loss)	600,000	700,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Realized loss	0
Unrealized gain (loss)	24,000
Total net gain (loss) on interest rate swaps	$24,000

Derivative_Instruments_Forward

Derivative Instruments - Forward Natural Gas Contracts and Interest Rate Swaps Recorded in Accrued Liabilities and Other Liabilities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Forward natural gas contracts recorded in current liabilities:
Gross amounts recognized	$1,382	$3,955
Gross amounts offset in consolidated balance sheets	-7
Net amounts presented in the consolidated balance sheets	1,375	3,955
Interest Rate Swaps [Member]
Forward natural gas contracts recorded in current liabilities:
Gross amounts recognized	629	653
Net amounts presented in the consolidated balance sheets	$629	$653

Derivative_Instruments_Schedul

Derivative Instruments - Schedule of Financial Instruments at Fair Value (Detail) (Level 2 [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Forward gas contracts	$1,375	$3,955
Interest Rate Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest rate swaps	$629	$653

Inventories_Inventories_Detail

Inventories - Inventories (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Finished goods	$39,157	$26,669
Raw materials	13,899	11,226
Other	238	190
Total inventory	$53,294	$38,085

Property_Plant_and_Equipment_P

Property, Plant and Equipment - Property, Plant and Equipment (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$588,029	$500,156
Less: Accumulated depreciation	-117,355	-107,705
Total property, plant and equipment, net	470,674	392,451
Land and land improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	28,072	28,042
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	46,486	45,516
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	490,249	406,489
Furniture, Fixtures and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,782	1,610
Computer equipment and computer software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,384	8,748
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,149	5,893
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,454	2,405
Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$1,453	$1,453

Property_Plant_and_Equipment_C

Property, Plant and Equipment - Construction in Progress (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Construction in progress	$110,540	$179,423
East Dubuque [Member]
Property, Plant and Equipment [Line Items]
Construction in progress	14,790	15,010
Pasadena [Member]
Property, Plant and Equipment [Line Items]
Construction in progress	207	32,747
Fulghum Fibers [Member]
Property, Plant and Equipment [Line Items]
Construction in progress	2,135	7,197
Atikokan Project [Member]
Property, Plant and Equipment [Line Items]
Construction in progress		36,931
Wawa Project [Member]
Property, Plant and Equipment [Line Items]
Construction in progress	66,944	65,232
Construction under QS Construction Facility [Member]
Property, Plant and Equipment [Line Items]
Construction in progress	25,698	21,712
Other Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Construction in progress	$766	$594

Property_Plant_and_Equipment_A

Property, Plant and Equipment - Additional Information (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
	t
Weyerhaeuser Corporation [Member]
Property, Plant and Equipment [Line Items]
Production of wood pellets	450,000,000,000
Atikokan Project [Member]
Property, Plant and Equipment [Line Items]
Production of wood pellets	110,000,000,000
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Portion of capitalized interest costs included in construction in progress	5.4	$6.30

Goodwill_Reconciliation_of_Cha

Goodwill - Reconciliation of Change in Carrying Value of Goodwill (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Jan. 23, 2015
Goodwill [Line Items]
Beginning Balance		$38,393
Ending Balance	40,255	38,393
Allegheny [Member]
Goodwill [Line Items]
Beginning Balance			1,862
Add: Allegheny Acquisition	1,862
Ending Balance			1,862
Fulghum [Member]
Goodwill [Line Items]
Beginning Balance		29,932
Ending Balance	29,932	29,932
Wood Pellets NEWP [Member]
Goodwill [Line Items]
Beginning Balance		8,461
Ending Balance	10,323	8,461
Wood Pellets NEWP [Member] | Allegheny [Member]
Goodwill [Line Items]
Add: Allegheny Acquisition	$1,862

Goodwill_Additional_Informatio

Goodwill - Additional Information (Detail) (Pasadena [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Pasadena [Member]
Goodwill [Line Items]
Accumulated impairment charges	$57.20	$57.20

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)	3 Months Ended	0 Months Ended
	Mar. 31, 2015	Jan. 23, 2015	Feb. 12, 2015	1-May-14	Apr. 16, 2014
Debt Instrument [Line Items]
Debt instrument interest rate description	Tranche A Loans under the A&R GSO Credit Agreement bear interest at a rate equal to the greater of (i) LIBOR plus 7.00% and (ii) 8.00% per annum. Tranche B Loans and Tranche C Loans under the A&R GSO Credit Agreement bear interest at a rate equal to the greater of (i) LIBOR plus 9.00% and (ii) 10.00% per annum. In the event the Borrower prepays any of the Loans on or prior to February 12, 2016, subject to certain exceptions, it will be required to pay a prepayment fee equal to 1.00% of the amount of the prepayment.
Interest rate of term loan	6.50%
Wood Pellets NEWP [Member]
Debt Instrument [Line Items]
Term loan period		5 years
Term loan amount		$8,000,000		$12,600,000
Term Loan [Member] | Wood Pellets NEWP [Member]
Debt Instrument [Line Items]
Debt instrument amortized period		7 years
A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Prepayment fee percentage			1.00%
Common units held by RNP owned by the borrower			10,682,246
Percentage of original issue discount on loan			2.00%
Minimum [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Limited liability company interest owned by loan parties			50.00%
Tranche A [Member] | Minimum [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility libor plus interest rate percentage			7.00%
Line of credit facility interest rate percentage			8.00%
Tranche B [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Term loan drawn			25,000,000
Tranche B [Member] | Minimum [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility libor plus interest rate percentage			9.00%
Line of credit facility interest rate percentage			10.00%
Tranche C [Member] | Minimum [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility libor plus interest rate percentage			9.00%
Line of credit facility interest rate percentage			10.00%
London Interbank Offered Rate (LIBOR) [Member] | Wood Pellets NEWP [Member]
Debt Instrument [Line Items]
Interest rate of term loan		2.25%
RNHI [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Term loan maturity date			9-Apr-19
Number of tranches of term loans			3
RNHI [Member] | A&R GSO Credit Agreement [Member] | Unplanned downtime and repairs [Member]
Debt Instrument [Line Items]
Cash distribution			13,000,000
RNHI [Member] | A&R GSO Credit Agreement [Member] | Lower product prices and higher raw material prices [Member]
Debt Instrument [Line Items]
Cash distribution			5,000,000
RNHI [Member] | Tranche A [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Term loan drawn					50,000,000
RNHI [Member] | Tranche B [Member] | Maximum [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Delayed draw term loan			45,000,000
RNHI [Member] | Tranche C [Member] | Maximum [Member] | A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Delayed draw term loan			18,000,000

Debt_Summary_of_Total_Debt_Det

Debt - Summary of Total Debt (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Long term debt outstanding	$506,670	$467,771
Plus: Unamortized net premium	446	1,085
Less: Current portion	18,652	17,784
Less: Current portion unamortized premium	-521	-524
Long-term debt	488,464	451,072
RNP Note Payable [Member]
Debt Instrument [Line Items]
Long term debt outstanding	320,000	320,000
Construction under QS Construction Facility [Member]
Debt Instrument [Line Items]
Long term debt outstanding	22,788	18,679
Fulghum [Member]
Debt Instrument [Line Items]
Long term debt outstanding	51,592	53,179
A&R GSO Credit Agreement [Member]
Debt Instrument [Line Items]
Long term debt outstanding	75,000	50,000
Wood Pellets NEWP [Member]
Debt Instrument [Line Items]
Long term debt outstanding	18,290	10,913
GE Credit Agreement [Member]
Debt Instrument [Line Items]
Long term debt outstanding	$19,000	$15,000

Commitments_and_Contingencies_1

Commitments and Contingencies - Commitments for Natural Gas Purchases (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
	MMBTU	MMBTU
Oil and Gas Delivery Commitments and Contracts [Line Items]
Total MMBtus under contracts	3,505,000	3,728,000
Commitments to purchase natural gas	$10,508	$15,568
Weighted average rate per MMBtu based on the fixed rates and the indexes applicable to each contract	3	4.18
MMBtus under Fixed-Price Contracts [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Total MMBtus under contracts	3,505,000	3,188,000
MMBtus under Index-Price Contracts [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Total MMBtus under contracts		540,000

Commitments_and_Contingencies_2

Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended	1 Months Ended	0 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Apr. 30, 2015	Feb. 25, 2015
	MMBTU	MMBTU	MMBTU	t
Other Commitments [Line Items]
Total MMBtus associated with additional forward purchase contracts	3,505,000	3,728,000
Weighted average rate per MMBtu	3	4.18
Estimated time of installation of ammonia safety flare	1-Dec-15
Cost of project under settlement agreement with environmental protection agency	$400,000
Estimated amount of penalty for settlement agreement	100,000
Property tax refund receivable		1,200,000
Property tax payable	400,000
Excess property tax assessed	300,000
Expected abandonment costs		800,000
Long term debt outstanding	506,670,000	467,771,000
Subsequent Event [Member]
Other Commitments [Line Items]
Total MMBtus associated with additional forward purchase contracts			1,600,000
Purchase commitments			4,100,000
Weighted average rate per MMBtu			2.66
Forward Gas Contracts [Member]
Other Commitments [Line Items]
Deposits, forward purchase contracts	700,000
Abener Teyma General Partnership [Member]
Other Commitments [Line Items]
Amount of change orders submitted	10,000,000
Quebec Stevedoring Company Limited [Member]
Other Commitments [Line Items]
Amount of change orders submitted	2,300,000
Long term debt outstanding	22,800,000
Contract obligation	15,800,000
2013 Drax Contract [Member]
Other Commitments [Line Items]
Guaranteed obligations	20,000,000
Contract term period	10 years
2013 Drax Contract [Member] | Wood Pellets Industrial [Member]
Other Commitments [Line Items]
Wood pallets required to sell from Wawa Facility to Drax	400,000
Ontario Power Generation [Member]
Other Commitments [Line Items]
Maximum quantity required to deliver under Drax	45,000
Contract term period	10 years
Maximum quantity required to deliver under Atikokan Facility	90,000
Canadian National Contract [Member]
Other Commitments [Line Items]
Location of Atikokan Facility from Port of Quebec	1,300
Location of Wawa Facility from Port of Quebec	1,100
Minimum rail carloads committed to transport thereafter	3,600
Penalty for delivery shortfalls per rail car	1,000
2015 Drax Contract [Member] | Wood Pellets Industrial [Member]
Other Commitments [Line Items]
Maximum quantity required to deliver under Drax				240,000
Price reduction on pellet shipment				900,000
Penalty paid				$170,000
Original pellet deliveries expected to deliver, year	Portions of the original 2015 pellet deliveries are being pushed to future years at 2015 pricing

Preferred_Stock_Additional_Inf

Preferred Stock - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Feb. 12, 2015
Class of Stock [Line Items]
Mezzanine, preferred stock, dividend rate	4.50%
Purchase price of the Series E preferred stock			$1,000
Increase in preferred stock authorized shares			9,453,314
Series E Preferred Stock [Member]
Class of Stock [Line Items]
Shares of preferred stock sold		100,000
Mezzanine, preferred stock, dividend rate	4.50%	4.50%
Purchase price per share			$2.22

Preferred_Stock_Schedule_of_Me

Preferred Stock - Schedule of Mezzanine Equity (Detail) (Mezzanine Equity [Member], USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Mezzanine Equity [Member]
Class of Stock [Line Items]
Original issue price of 2014 Preferred Stock	$100,000	$100,000
Less: Issuance costs	-3,020	-3,144
Less: Unamortized discount	-1,725	-1,796
Total mezzanine equity	$95,255	$95,060

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Tax [Line Items]
Income tax (benefit) expense	$1,694	$1,050
Effective tax rate	89.00%
Federal statutory rate	35.00%
RNP [Member]
Income Tax [Line Items]
Income tax (benefit) expense	$40

Segment_Information_Additional

Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015
	Segment
Segment Reporting [Abstract]
Number of operating segments	5

Segment_Information_Segment_In

Segment Information - Segment Information (Detail) (USD $)	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Segment net income	($4,949)				($6,988)
Total revenues	105,610	121,869	122,172	139,200	82,319	76,661	114,146	119,288	221,519	178,852	343,691	292,998	465,560	369,659
Total gross profit	24,309				17,895
Total segment selling, general and administrative expenses	14,504				15,572
Total segment depreciation and amortization	1,874				-324
Unallocated income (expense) recorded as other income (expense)	3				348
Total segment operating income	7,934				2,995
Total segment interest expense	5,917				5,845
Corporate income tax expense	-1,694				-1,050
Total segment net income (loss)	193				-4,123
Loss from discontinued operations, net of tax	-147				-1,471
Net income (loss)	46				-5,594
Total assets	860,085	828,150											828,150
Capital expenditures
Total capital expenditures	30,071				38,907
RNP [Member]
Segment Reporting Information [Line Items]
Total segment selling, general and administrative expenses	2,194				2,316
Unallocated income (expense) recorded as other income (expense)	-29
Total segment interest expense	5,009				4,982
Corporate income tax expense	-40
Parent Company [Member]
Segment Reporting Information [Line Items]
Total assets	1,787	1,982											1,982
Reportable Segments [Member]
Segment Reporting Information [Line Items]
Total segment selling, general and administrative expenses	8,447				6,431
Total segment depreciation and amortization recorded in operating expenses	1,731				-457
Total segment depreciation and amortization	9,680				4,308
Total segment other operating income	-4				-348
Total segment operating income	14,133				12,269
Total segment interest expense	814				560
Total segment net income (loss)	11,556				10,433
Capital expenditures
Total depreciation and amortization recorded in cost of sales	7,949				4,765
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Segment net income	11,556				10,433
Total assets	805,689	782,818											782,818
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total segment selling, general and administrative expenses	3,863				6,825
Total segment depreciation and amortization	143				133
Unallocated income (expense) recorded as other income (expense)	4				8
Total segment interest expense	94				304
Corporate income tax expense	-35				-4
RNP Partnership and Other [Member]
Segment Reporting Information [Line Items]
Total assets	40,507	34,071											34,071
Corporate and Unallocated Expenses Recorded as Selling, General and Administrative Expenses [Member]
Segment Reporting Information [Line Items]
Total assets	12,102	9,279											9,279
Capital expenditures
Total capital expenditures	155				159
East Dubuque [Member]
Capital expenditures
Total capital expenditures	6,973				5,677
East Dubuque [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	36,752				28,491
Total gross profit	17,441				12,398
Total segment selling, general and administrative expenses	1,346				1,133
Total segment depreciation and amortization recorded in operating expenses	69				37
Total segment other operating income	-4				-6
Total segment operating income	16,030				11,234
Total segment interest expense	19				22
Total segment net income (loss)	16,022				11,209
Total assets	194,591	186,508											186,508
Capital expenditures
Total depreciation and amortization recorded in cost of sales	3,239				2,205
Pasadena [Member]
Capital expenditures
Total capital expenditures	3,390				11,645
Pasadena [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	32,422				27,789
Total gross profit	1,342				1,366
Total segment selling, general and administrative expenses	796				1,829
Total segment depreciation and amortization recorded in operating expenses	360				296
Total segment operating income	186				-759
Total segment net income (loss)	163				-786
Total assets	197,104	193,737											193,737
Capital expenditures
Total depreciation and amortization recorded in cost of sales	1,475				766
Fulghum Fibers [Member]
Capital expenditures
Total capital expenditures	5,293				3,695
Fulghum Fibers [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	22,654				26,039
Total gross profit	3,707				4,131
Total segment selling, general and administrative expenses	1,682				1,401
Total segment depreciation and amortization recorded in operating expenses	981				-809
Total segment operating income	1,043				3,539
Total segment interest expense	539				537
Total segment net income (loss)	-1,107				1,654
Total assets	197,591	197,418											197,418
Capital expenditures
Total depreciation and amortization recorded in cost of sales	2,020				1,794
Wood Pellets Industrial [Member]
Capital expenditures
Total capital expenditures	13,858				17,731
Wood Pellets Industrial [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	1,664
Total gross profit	-404
Total segment selling, general and administrative expenses	3,919				2,068
Total segment depreciation and amortization recorded in operating expenses	43				19
Total segment other operating income					-342
Total segment operating income	-4,367				-1,745
Total segment interest expense	116				1
Total segment net income (loss)	-4,664				-1,644
Total assets	151,099	149,021											149,021
Capital expenditures
Total depreciation and amortization recorded in cost of sales	437
Wood Pellets NEWP [Member]
Segment Reporting Information [Line Items]
Total assets	65,304	56,134											56,134
Capital expenditures
Total capital expenditures	402
Wood Pellets NEWP [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	12,118
Total gross profit	2,223
Total segment selling, general and administrative expenses	704
Total segment depreciation and amortization recorded in operating expenses	278
Total segment operating income	1,241
Total segment interest expense	140
Total segment net income (loss)	1,142
Capital expenditures
Total depreciation and amortization recorded in cost of sales	$778

Segment_Information_Summary_of

Segment Information - Summary of Revenues by Geographic Area (Detail) (USD $)

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2014

Dec. 31, 2013

Segment Reporting Information [Line Items]

Total revenues

$105,610

$121,869

$122,172

$139,200

$82,319

$76,661

$114,146

$119,288

$221,519

$178,852

$343,691

$292,998

$465,560

$369,659

United States [Member]

Segment Reporting Information [Line Items]

Total revenues

94,813

70,479

Canada [Member]

Segment Reporting Information [Line Items]

Total revenues

1,664

Other [Member]

Segment Reporting Information [Line Items]

Total revenues

$9,133

Segment_Information_Summary_of1

Segment Information - Summary of Assets by Geographic Area (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Segment Reporting Information [Line Items]
Total assets	$860,085	$828,150
United States [Member]
Segment Reporting Information [Line Items]
Total assets	664,638	637,271
Canada [Member]
Segment Reporting Information [Line Items]
Total assets	151,128	149,021
Other [Member]
Segment Reporting Information [Line Items]
Total assets	$44,319	$41,858

Segment_Information_Segment_In1

Segment Information - Segment Information (Parenthetical) (Detail) (USD $)	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenues	$105,610	$121,869	$122,172	$139,200	$82,319	$76,661	$114,146	$119,288	$221,519	$178,852	$343,691	$292,998	$465,560	$369,659
Increase (decrease) in revenue and cost of goods sold					2,512								7,100	4,700
Fulghum Fibers [Member]
Segment Reporting Information [Line Items]
Increase (decrease) in revenue and cost of goods sold					2,512
As Reported [Member]
Segment Reporting Information [Line Items]
Total revenues		122,636	125,304	139,890	84,831	79,067	115,657	120,061	224,721	179,625	350,025	295,282	472,661	374,349
As Reported [Member] | Fulghum Fibers [Member]
Segment Reporting Information [Line Items]
Total revenues					28,551
Other [Member]
Segment Reporting Information [Line Items]
Total revenues	9,133
Other [Member] | As Reported [Member] | Fulghum Fibers [Member]
Segment Reporting Information [Line Items]
Total revenues					$14,352

Net_Income_Loss_Per_Common_Sha

Net Income (Loss) Per Common Share Allocated to Rentech - Schedule of Earnings Per Share, Basic and Diluted (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Loss from continuing operations attributable to Rentech common shareholders	($4,802)	($5,517)
Less: Income from continuing operations allocated to participating securities	0	0
Loss from continuing operations allocated to common shareholders	-4,802	-5,517
Numerator:
Loss from discontinued operations attributable to Rentech common shareholders	-147	-1,471
Less: Income from discontinued operations allocated to participating securities	0	0
Loss from discontinued operations allocated to common shareholders	-147	-1,471
Numerator:
Net loss attributable to Rentech common shareholders	-4,949	-6,988
Less: Income allocated to participating securities	0	0
Net loss allocated to common shareholders	($4,949)	($6,988)
Denominator:
Weighted average common shares outstanding	229,362	227,529
Effect of dilutive securities:
Diluted shares outstanding	229,362	227,529
Continuing operations	($0.02)	($0.02)
Discontinued operations	$0	($0.01)
Basic net loss per common share	($0.02)	($0.03)
Continuing operations	($0.02)	($0.02)
Discontinued operations	$0	($0.01)
Diluted net loss per common share	($0.02)	($0.03)
Common Stock Options [Member]
Effect of dilutive securities:
Effect of dilutive securities	0	0
Restricted Stock [Member]
Effect of dilutive securities:
Effect of dilutive securities	0	0
Preferred Stock [Member]
Effect of dilutive securities:
Effect of dilutive securities	0	0
Warrants [Member]
Effect of dilutive securities:
Effect of dilutive securities	0	0

Net_Income_Loss_Per_Common_Sha1

Net Income (Loss) Per Common Share Allocated to Rentech - Additional Information (Detail)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Anti-dilutive common stock	60.5	16

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)	3 Months Ended	0 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	31-May-15	Apr. 30, 2015
Subsequent Event [Line Items]
Date of declaration for distribution of cash to partnership's common unitholders	11-May-15
Date of distribution for distribution of cash to common unitholders	29-May-15
Unitholders distribution record date	22-May-15
Subsequent Event [Member]
Subsequent Event [Line Items]
Cash distribution per unit declared to the partnership's common unitholders		$0.36
Total distributions to partnership's common unitholders		$14.10
Subsequent Event [Member] | A&R GSO Credit Agreement [Member]
Subsequent Event [Line Items]
Additional borrowing			7.5
Subsequent Event [Member] | RNHI [Member]
Subsequent Event [Line Items]
Received distributions to partnership's common unitholders		$8.40