Molycorp (MCPIQ) 10-K 3 Mar 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 28, 2014	Jun. 30, 2013
Document and Entity Information [Abstract]	'	'	'
Entity Registrant Name	'Molycorp, Inc.	'	'
Entity Central Index Key	'0001489137	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Amendment Flag	'false	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	240,558,024	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Public Float	'	'	$787,228,489

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'
Cash and cash equivalents	$227,790
Trade accounts receivable, net (Note 2)	52,430
Inventory (Note 5)	287,376
Deferred charges (Note 15)	9,412
Deferred tax assets (Note 15)	9,789
Income tax receivable	25,087
Prepaid expenses and other current assets	21,794
Total current assets	633,678
Non-current assets:	'
Deposits (Note 6)	26,769
Property, plant and equipment, net (Note 7)	1,544,304
Inventory (Note 5)	26,096
Intangible assets, net (Note 9)	450,938
Deferred tax assets (Note 15)	0
Investments	64,036
Goodwill (Note 9)	239,742
Other non-current assets	6,972
Total non-current assets	2,358,857
Total assets	2,992,535
Current liabilities:	'
Trade accounts payable	241,994
Accrued expenses (Note 12)	59,013
Income tax payable	15,267
Deferred tax liabilities (Note 15)	0
Debt and capital lease obligations (Note 14)	39,604
Other current liabilities	3,539
Total current liabilities	359,417
Non-current liabilities:	'
Asset retirement obligation (Note 13)	18,586
Deferred tax liabilities (Note 15)	160,675
Debt and capital lease obligations (Note 14)	1,188,832
Derivative liability (Note 24)	7,816
Pension liabilities (Note 25)	3,292
Other non-current liabilities	2,659
Total non-current liabilities	1,381,860
Total liabilities	1,741,277
Commitments and contingencies (Note 19)	'
Stockholders’ equity:	'
Common stock, $0.001 par value; 350,000,000 shares authorized at December 31, 2013 (Note 16)	139
Preferred stock, $0.001 par value; 5,000,000 shares authorized at December 31, 2013 (Note 16)	2
Additional paid-in capital	1,691,429
Accumulated other comprehensive loss	-9,433
Accumulated deficit	-466,091
Total Molycorp stockholders’ equity	1,216,046
Noncontrolling interests	35,212
Total stockholders’ equity	1,251,258
Total liabilities and stockholders’ equity	$2,992,535

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013
Statement of Financial Position [Abstract]	'
Common stock, par value	$0.00
Common stock, authorized	350,000,000
Preferred stock, par value	$0.00
Preferred stock, authorized	5,000,000

Consolidated_Statements_of_Ope

Consolidated Statements of Operations and Comprehensive Income (USD $)

3 Months Ended

12 Months Ended

In Thousands, except Per Share data, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Income Statement [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Revenues

$123,814

$149,066

$136,112

$145,398

$133,611

$205,205

$104,410

$84,470

$554,390

$527,696

$396,831

Costs of sales:

'

'

'

'

'

'

'

'

'

'

'

Costs excluding depreciation and amortization

'

'

'

'

'

'

'

'

-553,831

-478,253

-164,351

Depreciation and amortization

'

'

'

'

'

'

'

'

-67,727

-30,621

-13,539

Gross (loss) profit

-27,049

-17,778

-18,036

-4,305

-19,703

11,494

-3,996

31,027

-67,168

18,822

218,941

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Selling, general and administrative

'

'

'

'

'

'

'

'

-107,169

-113,437

-50,757

Corporate development

'

'

'

'

'

'

'

'

-247

-19,796

-5,912

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-38,037

-22,187

-1,688

Research and development

'

'

'

'

'

'

'

'

-23,172

-27,796

-7,718

Impairment of goodwill and other long-lived assets

'

'

'

'

'

'

'

'

-120,898

-301,755

0

Operating (loss) income

'

'

'

'

'

'

'

'

-356,691

[1]

-466,149

[1]

152,866

Other (expense) income:

'

'

'

'

'

'

'

'

'

'

'

Other income (expense)

'

'

'

'

'

'

'

'

-7,525

-38,798

-153

Foreign exchange gain (loss), net

'

'

'

'

'

'

'

'

-376

2,872

-5,415

Interest expense, net of capitalized interest

'

'

'

'

'

'

'

'

-67,684

-22,116

-388

Total other expense

'

'

'

'

'

'

'

'

-75,585

-58,042

-5,956

(Loss) income from continuing operations before income taxes and equity earnings

-228,592

[2]

-76,181

[2]

-70,254

[2]

-57,249

[2]

-381,902

[3]

-42,984

[3]

-93,871

[3]

-5,434

[3]

-432,276

-524,191

146,910

Income tax benefit (expense)

'

'

'

'

'

'

'

'

70,943

54,075

-28,576

Equity in results of affiliates

'

'

'

'

'

'

'

'

-9,169

-3,490

0

(Loss) income from continuing operations

'

'

'

'

'

'

'

'

-370,502

-473,606

118,334

Loss from discontinued operations, net of tax

'

'

'

'

'

'

'

'

-6,427

-1,737

0

Net (loss) income

-198,288

-69,799

-70,689

-38,153

-389,490

-15,451

-66,924

-3,478

-376,929

-475,343

118,334

Net loss (income) attributable to noncontrolling interests

'

'

'

'

'

'

'

'

2,546

-5,826

-808

Net (loss) income attributable to Molycorp stockholders

-194,308

-69,929

-71,175

-38,971

-391,196

-18,891

-67,604

-3,478

-374,383

-481,169

117,526

Other comprehensive income (loss), net of tax:

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments

'

'

'

'

'

'

'

'

1,623

248

-8,481

Actuarial gain (loss)

'

'

'

'

'

'

'

'

1,359

-1,200

0

Comprehensive (loss) income

'

'

'

'

'

'

'

'

-373,947

-476,295

109,853

Comprehensive (loss) income attributable to:

'

'

'

'

'

'

'

'

'

'

'

Molycorp stockholders

'

'

'

'

'

'

'

'

-376,493

-470,469

109,468

Noncontrolling interests

'

'

'

'

'

'

'

'

2,546

-5,826

385

Comprehensive (loss) income

'

'

'

'

'

'

'

'

($373,947)

($476,295)

$109,853

Basic:

'

'

'

'

'

'

'

'

'

'

'

Continuing operations (in dollars per share)

'

'

'

'

'

'

'

'

($2.17)

($4.58)

$1.29

Discontinued operations (in dollars per share)

'

'

'

'

'

'

'

'

($0.04)

($0.02)

$0

Basic (in dollars per share)

($0.95)

($0.43)

($0.44)

($0.27)

($3.16)

($0.19)

($0.71)

($0.07)

($2.21)

($4.60)

$1.29

Diluted:

'

'

'

'

'

'

'

'

'

'

'

Continuing operations (in dollars per share)

'

'

'

'

'

'

'

'

($2.17)

($4.58)

$1.27

Discontinued operations (in dollars per share)

'

'

'

'

'

'

'

'

($0.04)

($0.02)

$0

Diluted (in dollars per share)

($0.95)

($0.43)

($0.44)

($0.27)

($3.16)

($0.19)

($0.71)

($0.07)

($2.21)

($4.60)

$1.27

[1]

Includes impairment of goodwill and other long-lived assets in some segments. See notes 7 and 9 below for details.

[2]

Includes the following impairment charges in the fourth quarter: goodwill, $11.0 million; rare earths quotas, $67.2 million; patents, $10.2 million; exploration rights, $16.2 million; cost-method investments $9.4 million and long-lived tangible assets, $16.3 million.

[3]

The sum of the quarterly income (loss) per share may be different than the per share amount for the year as the calculation for each quarter is based on the weighted average shares outstanding for that period.

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)

Total

Molymet

Molycorp Silmet

Total Molycorp Stockholders' Equity

Total Molycorp Stockholders' Equity

Total Molycorp Stockholders' Equity

Total Molycorp Stockholders' Equity

Common Stock

Common Stock

Common Stock

Common Stock

Series A Mandatory Convertible Preferred Stock

Additional Paid-In Capital

Additional Paid-In Capital

Additional Paid-In Capital

Additional Paid-In Capital

Accumulated Other Comprehensive Loss

Accumulated deficit

Non controlling interests

Non controlling interests

Non controlling interests

In Thousands, except Share data, unless otherwise specified

Molymet

Molycorp Silmet

Molycorp Canada

Molymet

Molycorp Silmet

Molycorp Canada

Molymet

Molycorp Silmet

Molycorp Canada

Molycorp Silmet

Molycorp Canada

Balance at the beginning of period at Dec. 31, 2010

$446,513

'

'

$446,513

'

'

'

$82

'

'

'

$0

$539,866

'

'

'

$0

($93,435)

$0

'

'

Balance at the beginning of the period (in shares) at Dec. 31, 2010

'

'

'

'

'

'

'

82,291,200

'

'

'

0

'

'

'

'

'

'

'

'

'

Increase (Decrease) in Stockholders' Equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of Series A mandatory convertible preferred stock at $100.00 per share, net of underwriting fees and other offering costs

199,642

'

'

199,642

'

'

'

'

'

'

'

2

199,640

'

'

'

'

'

'

'

'

Sale of Series A mandatory convertible preferred stock, net of underwriting fees and other offering costs (in shares)

'

'

'

'

'

'

'

'

'

'

'

2,070,000

'

'

'

'

'

'

'

'

'

Stock-based compensation

4,671

'

'

4,671

'

'

'

0

'

'

'

'

4,671

'

'

'

'

'

'

'

'

Stock-based compensation (in shares)

'

'

'

'

'

'

'

11,424

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of shares for interest in subsidiary

'

'

81,475

'

'

72,655

'

'

'

2

'

'

'

'

72,653

'

'

'

'

8,820

'

Issuance of shares for interest in subsidiary, (in shares)

'

'

'

'

'

'

'

'

'

1,593,419

'

'

'

'

'

'

'

'

'

'

'

Component of 6.00% convertible notes (Note 14)

36,227

'

'

36,227

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred taxes on component of convertible debt

-14,138

'

'

-14,138

'

'

'

'

'

'

'

'

-14,138

'

'

'

'

'

'

'

'

Net (loss) income

118,334

'

'

117,526

'

'

'

'

'

'

'

'

'

'

'

'

'

117,526

808

'

'

Preferred dividends

-9,013

'

'

-9,013

'

'

'

'

'

'

'

'

'

'

'

'

'

-9,013

'

'

'

Other comprehensive loss

-8,481

'

'

-8,058

'

'

'

'

'

'

'

'

'

'

'

'

-8,058

'

-423

'

'

Acquisition of noncontrolling interests in Silmet

-10,000

'

'

-795

'

'

'

'

'

'

'

'

-372

'

'

'

-423

'

-9,205

'

'

Balance at the end of the period at Dec. 31, 2011

845,230

'

'

845,230

'

'

'

84

'

'

'

2

838,547

'

'

'

-8,481

15,078

0

'

'

Balance at the end of the period (in shares) at Dec. 31, 2011

'

'

'

'

'

'

'

83,896,043

'

'

'

2,070,000

'

'

'

'

'

'

'

'

'

Increase (Decrease) in Stockholders' Equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of shares

'

390,093

'

'

390,093

'

'

'

12

'

'

'

'

390,081

'

'

'

'

'

'

'

Issuance of shares (in shares)

'

'

'

'

'

'

'

'

12,500,000

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of shares for conversion of convertible securities, value

4,527

'

'

4,527

'

'

'

'

'

'

'

'

4,527

'

'

'

'

'

'

'

'

Issuance of shares for conversion of convertible securities, shares

'

'

'

'

'

'

'

99,723

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock-based compensation

3,434

'

'

3,434

'

'

'

0

'

'

'

'

3,434

'

'

'

'

'

'

'

'

Stock-based compensation (in shares)

'

'

'

'

'

'

'

3,740

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of shares for interest in subsidiary

334,887

'

'

'

'

'

284,144

'

'

'

14

'

'

'

'

284,130

'

'

'

'

50,743

Issuance of shares for interest in subsidiary, (in shares)

'

'

'

'

'

'

'

'

'

'

13,885,622

'

'

'

'

'

'

'

'

'

'

Issuance of shares for acquisition of exploration rights (Note 8)

8,000

'

'

8,000

'

'

'

1

'

'

'

'

7,999

'

'

'

'

'

'

'

'

Issuance of shares for acquisition of exploration rights (Note 8) (in shares)

'

'

'

'

'

'

'

788,410

'

'

'

'

'

'

'

'

'

'

'

'

'

Component of 6.00% convertible notes (Note 14)

68,695

'

'

68,695

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred taxes on component of convertible debt

-27,106

'

'

-27,106

'

'

'

'

'

'

'

'

-27,106

'

'

'

'

'

'

'

'

Issuance of 2013 Primary Shares (Note 16)

132,130

'

'

132,130

'

'

'

14

'

'

'

'

132,116

'

'

'

'

'

'

'

'

Issuance of 2013 Primary Shares (Note 16) (in shares)

'

'

'

'

'

'

'

13,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Borrowed Shares (Note 16)

25

'

'

25

'

'

'

14

'

'

'

'

11

'

'

'

'

'

'

'

'

Issuance of Borrowed Shares (Note 16) (in shares)

'

'

'

'

'

'

'

13,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Net (loss) income

-475,343

'

'

-481,169

'

'

'

'

'

'

'

'

'

'

'

'

'

-481,169

5,826

'

'

Preferred dividends

-11,385

'

'

-11,385

'

'

'

'

'

'

'

'

-11,385

'

'

'

'

'

'

'

'

Distribution to noncontrolling interests

-5,977

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

-5,977

'

'

Other comprehensive loss

-952

'

'

-952

'

'

'

'

'

'

'

'

'

'

'

'

-952

'

'

'

'

Acquisition of noncontrolling interests in Silmet

-15,000

'

'

380

'

'

'

'

'

'

'

'

380

'

'

'

'

'

-15,380

'

'

Balance at the end of the period at Dec. 31, 2012

1,251,258

'

'

1,216,046

'

'

'

139

'

'

'

2

1,691,429

'

'

'

-9,433

-466,091

35,212

'

'

Balance at the end of the period (in shares) at Dec. 31, 2012

'

'

'

'

'

'

'

138,773,538

'

'

'

2,070,000

'

'

'

'

'

'

'

'

'

Increase (Decrease) in Stockholders' Equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of shares

247,567

'

'

247,567

'

'

'

52

'

'

'

'

247,515

'

'

'

'

'

'

'

'

Issuance of shares (in shares)

'

'

'

'

'

'

'

51,750,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of shares for conversion of convertible securities, value

18

'

'

18

'

'

'

'

'

'

'

'

18

'

'

'

'

'

'

'

'

Issuance of shares for conversion of convertible securities, shares

'

'

'

'

'

'

'

2,471

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of Exchangeable Shares (Note 16) (in shares)

'

'

'

'

'

'

'

18,616

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock-based compensation

5,392

'

'

5,392

'

'

'

'

'

'

'

'

5,392

'

'

'

'

'

'

'

'

Stock-based compensation (in shares)

'

'

'

'

'

'

'

43,803

'

'

'

'

'

'

'

'

'

'

'

'

'

Component of 6.00% convertible notes (Note 14)

21,815

'

'

21,815

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred taxes on component of convertible debt

-8,508

'

'

-8,508

'

'

'

'

'

'

'

'

-8,508

'

'

'

'

'

'

'

'

Issuance of 2013 Primary Shares (Note 16)

248,172

'

'

248,172

'

'

'

43

'

'

'

'

248,129

'

'

'

'

'

'

'

'

Issuance of 2013 Primary Shares (Note 16) (in shares)

'

'

'

'

'

'

'

43,125,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Borrowed Shares (Note 16)

7

'

'

7

'

'

'

7

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Borrowed Shares (Note 16) (in shares)

'

'

'

'

'

'

'

6,666,666

'

'

'

'

'

'

'

'

'

'

'

'

'

Net (loss) income

-376,929

'

'

-374,383

'

'

'

'

'

'

'

'

'

'

'

'

'

-374,383

-2,546

'

'

Preferred dividends

-11,385

'

'

-11,385

'

'

'

'

'

'

'

'

-11,385

'

'

'

'

'

'

'

'

Other

1,219

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,219

'

'

Distribution to noncontrolling interests

-4,546

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-4,546

'

'

Other comprehensive loss

2,982

'

'

2,982

'

'

'

'

'

'

'

'

'

'

'

'

2,982

'

'

'

'

Balance at the end of the period at Dec. 31, 2013

$1,377,062

'

'

$1,347,723

'

'

'

$241

'

'

'

$2

$2,194,405

'

'

'

($6,451)

($840,474)

$29,339

'

'

Balance at the end of the period (in shares) at Dec. 31, 2013

'

'

'

'

'

'

'

240,380,094

'

'

'

2,070,000

'

'

'

'

'

'

'

'

'

Consolidated_Statement_of_Stoc

Consolidated Statement of Stockholders' Equity (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2011	Jun. 15, 2011	Dec. 31, 2013	Jan. 30, 2013
	Series A Mandatory Convertible Preferred Stock	3.25% Convertible Notes	3.25% Convertible Notes	3.25% Convertible Notes	5.50% Convertible Senior Notes due 2018	5.50% Convertible Senior Notes due 2018
		Convertible Debt	Convertible Debt	Convertible Debt	Convertible Debt	Convertible Debt
Price per share of stock sold (in dollars per share)	$100	'	'	'	'	'
Interest rate	'	3.25%	3.25%	3.25%	5.50%	5.50%

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:	'	'	'
Net (loss) income	($376,929,000)	($475,343,000)	$118,334,000
Adjustments to reconcile net (loss) income to net cash from operating activities:	'	'	'
Depreciation, amortization and accretion	105,764,000	52,808,000	15,227,000
Deferred income tax (benefit) expense	-68,290,000	-23,563,000	2,924,000
Inventory write-downs	100,346,000	83,039,000	3,776,000
Release of inventory step-up value	3,068,000	24,729,000	10,200,000
Impairment of goodwill and other long-lived assets	120,898,000	301,755,000	0
Impairment of cost-method investment	9,411,000	0	0
Stock-based compensation	5,392,000	3,434,000	4,671,000
Allowance for doubtful accounts	0	2,556,000	0
Foreign exchange loss	-454,000	1,988,000	5,415,000
Equity in results of affiliates	9,169,000	3,490,000	0
Other operating activities	1,993,000	-4,648,000	2,607,000
Net change in operating assets and liabilities (Note 22)	-64,719,000	-59,880,000	-120,189,000
Net cash (used in) provided by operating activities	-154,351,000	-89,635,000	42,965,000
Cash flows from investing activities:	'	'	'
Cash paid in connection with acquisitions, net of cash acquired	0	-591,011,000	-30,023,000
Investment in joint ventures	-3,423,000	-33,044,000	0
Deposits	0	-3,999,000	2,897,000
Cash paid to acquire non-marketable securities	0	0	-20,000,000
Capital expenditures	-379,312,000	-791,469,000	-302,180,000
Acquisition of exploration rights	0	-8,167,000	0
Other investing activities	5,477,000	4,761,000	-84,000
Net cash used in investing activities	-377,258,000	-1,422,929,000	-349,390,000
Cash flows from financing activities:	'	'	'
Issuance of shares to Molymet	0	390,093,000	0
Repayments of short-term borrowings—related party	0	0	-3,150,000
Repayments of debt	-26,823,000	-228,708,000	-4,428,000
Net proceeds from sale of preferred stock	0	0	199,642,000
Net proceeds from sale of common stock	495,717,000	132,130,000	0
Issuance of Senior Secured Notes	'	635,373,000	'
Issuance of 5.50% Convertible Notes	165,600,000	395,712,000	223,100,000
Payments of preferred dividends	-11,385,000	-11,385,000	-9,015,000
Distribution paid to noncontrolling interests	-4,546,000	-5,977,000	0
Proceeds from debt	0	14,699,000	5,131,000
Other financing activities	-1,297,000	-1,554,000	0
Net cash provided by financing activities	617,266,000	1,320,383,000	411,280,000
Effect of exchange rate changes on cash	870,000	1,116,000	-2,430,000
Net change in cash and cash equivalents	86,527,000	-191,065,000	102,425,000
Cash and cash equivalents at beginning of the period	227,790,000	418,855,000	316,430,000
Cash and cash equivalents at end of period	314,317,000	227,790,000	418,855,000
5.50% Convertible Senior Notes due 2018 | Convertible Debt	'	'	'
Cash flows from financing activities:	'	'	'
Issuance of 5.50% Convertible Notes	165,600,000	0	0
10% Senior Securied Notes, net of discount, due June 2020 | Senior Notes	'	'	'
Cash flows from financing activities:	'	'	'
Issuance of Senior Secured Notes	0	635,373,000	0
6.00% Convertible Notes | Convertible Debt	'	'	'
Cash flows from financing activities:	'	'	'
Issuance of 5.50% Convertible Notes	0	395,712,000	0
3.25% Convertible Notes | Convertible Debt	'	'	'
Cash flows from financing activities:	'	'	'
Issuance of 5.50% Convertible Notes	$0	$0	$223,100,000

Company_Background

Company Background	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Company Background	'
	Company Background
	Molycorp, Inc. (“Molycorp” or the “Company”) is a leading global rare earths producer that operates a vertically integrated, global supply chain that combines a world-class rare earths resource with manufacturing facilities on three continents that can produce a wide variety of custom engineered, advanced rare earth materials from all of the lanthanide elements, plus yttrium.
	The Company employs approximately 2,580 individuals at 26 locations in 11 countries. Molycorp's vertical integration allows it to operate multiple product supply chains, serve as a highly reliable supplier of advanced rare earths and rare metal materials, and provide price visibility to customers worldwide.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Use of Estimates
	The preparation of the Company's consolidated financial statements, in accordance with generally accepted accounting principles in the United States of America (“GAAP”), requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases its estimates on the Company’s historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ significantly from these estimates under different assumptions and conditions.
	Significant estimates made by management in the accompanying financial statements include: the collectability of accounts receivable; the realizability of inventory; the useful lives and recoverability of long-lived assets such as property, plant and equipment, capital leases, intangible assets, including goodwill, and investments; the determination of uncertain tax positions; the fair values of assets acquired and liabilities assumed in business combinations; and the adequacy of the asset retirement obligation.
	Basis of Presentation
	The consolidated financial statements include the accounts of Molycorp and its majority-owned subsidiaries where it exerts control. Investments in which Molycorp does not have control and is not considered to be the primary beneficiary of a variable interest entity, but it exercises significant influence over the operating and financial policies of the investee, are accounted for using the equity method of accounting. All other investments are accounted for using the cost method of accounting. All intercompany balances and transactions are eliminated in consolidation.
	Prior period amounts of "Other comprehensive income (loss)" in the consolidated statements of operations and comprehensive income, and certain prior period adjustments to reconcile net (loss) income to net cash from operating activities in the consolidated statements of cash flows have been reclassified to conform to the current period presentation. Such reclassifications did not affect results of operations.
	The Company exited development stage status in the second quarter of 2012. At that time, its planned principal operations at the Molycorp Mountain Pass Rare Earth Facility (the "Molycorp Mountain Pass facility") had effectively commenced with the transition to production from recently-mined rare earth ore. The Company's revenues began to significantly increase as a result of the acquisition of Molycorp Canada (see Note 11).
	Revenues and Costs of Sales
	Revenues are recognized when persuasive evidence of an arrangement exists, the risks and rewards of ownership have been transferred to the customer, which is generally when title passes, the selling price is fixed or determinable, and collection is reasonably assured. Title generally passes to the customer upon shipment of product from the Company’s facilities. Prices are generally set at the time of, or prior to, shipment. Transportation and distribution costs are incurred only on sales for which the Company is responsible for delivering the product.
	Costs of sales include costs of production and write downs of inventory to net realizable value. Primary production costs include labor, raw materials, depreciation, supplies, maintenance costs and plant overhead.
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash and liquid investments with an original maturity of three months or less. Because of the short maturity of these investments, the carrying amounts approximate their fair values.
	Trade Accounts Receivable
	Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The Company reviews the need for an allowance for doubtful accounts quarterly based on historical experience with each customer and the specifics of each arrangement. At December 31, 2013 and 2012, the allowance for doubtful accounts was $2.6 million.
	Inventory
	Inventory consists of stockpiles of crushed ore, bastnasite concentrate, raw materials, work in process, finished goods and materials and supplies. Inventory cost is determined using the lower of weighted average cost or estimated net realizable value, and includes all expenses directly attributable to the manufacturing process as well as production overheads based on normal operating capacity. The Company evaluates the carrying value of inventory each quarter giving consideration to slow-moving items, obsolescence, excessive levels, and other factors and recognizes related write-downs as necessary. Write-downs of inventory to estimated net realizable value are charged to costs of sales. Inventory expected to be used and sold beyond a twelve-month period is classified as a non-current asset in the consolidated balance sheets.
	Property, Plant and Equipment
	Property, plant and equipment obtained in business acquisitions are recorded at their estimated fair value as of the acquisition date. Expenditures for new property, plant and equipment, and improvements that extend the useful life or functionality of the asset are recorded at their cost of acquisition or construction. Depreciation on plant and equipment is provided using the straight-line method over their estimated useful lives (buildings and improvements - generally 4 to 40 years; plant and equipment - 2 to 15 years). Maintenance costs are expensed as incurred.
	Construction in progress includes costs directly attributable to the construction or development of long-term tangible assets. These costs may include: labor and employee benefits associated with the construction of the asset; site preparation; permitting; engineering; installation and assembly; procurement; insurance; legal; commissioning; and interest on borrowings to finance the construction of the asset. Depreciation is not recorded on the related assets until they are placed in service or ready for their intended use.
	Gains or losses arising on the disposal of property, plant and equipment are determined as the difference between the proceeds from disposal and the carrying amount of the asset, and are included in other income (expense) in the consolidated statements of operations and comprehensive income.
	Mineral Properties and Development Costs
	Mineral properties and development costs, which are referred to collectively as mineral properties, include acquisition costs, drilling costs, and the cost of other development work, all of which are capitalized. The Company depletes mineral properties using the units of production method over estimated proven and probable reserves. Proven and probable reserves are based on extensive drilling, sampling, mine modeling, and mineral recovery from which economic feasibility has been determined, and are estimated based on information available at the time the reserves are calculated. Proven and probable reserves are based on estimates, and no assurance can be given that the indicated levels of rare earths will be realized or that production costs and estimated future development costs will not exceed the net realizable value of the products. Reserve estimates may require revisions based on actual production experience. Market price fluctuations of rare earths, as well as increased production costs or reduced recovery rates, could render proven and probable reserves containing relatively lower grades of mineralization uneconomic to exploit and might result in a reduction of reserves. Depletion expense is an inventoriable cost.
	Intangible Assets
	Intangible assets consist primarily of customer relationships, Chinese rare earths quotas, patents, Chinese land use rights and both indefinite-lived and finite-lived trade names. The Chinese rare earths quotes were written off in December 2013. Finite-lived intangible assets are amortized on a straight-line basis over the estimated useful lives. Useful lives of the Company's finite-lived intangible assets currently range from 2 to 16 years for customer relationships, patents and trade name, and 50 years for Chinese land use rights.
	Recoverability of Long-Lived Depreciable/Amortizable Assets
	Long-lived assets such as property, plant, and equipment, mineral properties and intangible assets that are depreciated or amortized, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. An impairment is considered to exist if the total undiscounted future cash flows expected from the use of the asset or asset group are less than its carrying amount. An impairment loss, if any, is recorded for the excess of the asset's or asset group's carrying value over its fair value, as determined by a valuation technique appropriate to the given circumstances.
	Recoverability of Goodwill
	The Company assigns goodwill arising from acquired companies to the reporting units that are expected to benefit from the acquisition. On an annual basis or in interim periods when circumstances require, the Company tests the recoverability of its goodwill utilizing a two-step impairment analysis. Under this analysis, the Company initially compares the fair value of each identified reporting unit with the reporting unit's carrying value. The Company's reporting units are determined either at the operating segment level or a component one level below the operating segment that constitutes a business for which the operating segment's management generally reviews production and financial results. To the extent that a reporting unit's fair value is less than its carrying value, the Company performs an additional step to determine the implied fair value of the reporting unit's goodwill. The implied fair value of goodwill is calculated by first allocating the reporting unit's fair value to its assets and liabilities, excluding goodwill, and then comparing the excess of the reporting unit's fair value to the carrying value of goodwill. To the extent that the carrying value of goodwill exceeds its implied fair value, the Company would recognize an impairment loss. The valuation methodology utilized to determine the fair value of the Company's reporting units is based on a discounted cash flow model, or income approach, in which expected future net cash flows, excluding any financing costs or dividends, are discounted using an appropriate discount rate. The income approach is dependent upon a number of significant management estimates about future performance including expected sales volumes, sales prices, production costs, income taxes, capital expenditures, working capital changes, foreign exchange rates and the after-tax weighted average cost of capital. Changes in any of these assumptions could materially impact the estimated fair value of the Company's reporting units. Discount factors are determined individually for each reporting unit to reflect its respective risk profile as assessed by the Company's management.
	Investments
	Investments in non-marketable equity securities of entities in which the Company has the ability to exercise significant influence over the entity's operating and financial policies are accounted for by the equity method. The Company recognizes its proportionate share of the entity’s income or loss each period with such amounts included in "Equity in results of affiliate" in the consolidated statements of operations and comprehensive income. Equity method investments are reviewed periodically for other-than-temporary decline in value. Investments in non-marketable equity securities of entities for which the Company does not have the ability to exercise significant influence over the entity’s operations and financial policies are accounted for by the cost method. Cost method investments are carried at cost and are subject to other-than-temporary impairment assessments.
	Business Combinations
	The Company accounts for all business combinations using the acquisition method of accounting. Under this method, assets and liabilities, including any noncontrolling interests, are recognized at fair value at the date of acquisition. The excess of the purchase price over the fair value of assets acquired, net of liabilities assumed, and noncontrolling interests is recognized as goodwill. Certain adjustments to the assessed fair values of the assets, liabilities, or noncontrolling interests made subsequent to the acquisition date, but within the measurement period, which is up to one year, are recorded as adjustments to goodwill. Any adjustments subsequent to the measurement period are recorded in income. Any cost or equity method interest that the Company holds in the acquired company prior to the acquisition is remeasured to fair value at acquisition with a resulting gain or loss recognized in income for the difference between fair value and the existing book value. Results of operations of the acquired entity are included in the Company’s results from the date of the acquisition. The Company expenses all costs as incurred related to an acquisition under “Corporate development” in the consolidated statement of operations and comprehensive income.
	Asset Retirement Obligation
	The Company accounts for reclamation costs, along with other costs related to the closure of the Molycorp Mountain Pass facility, in accordance with ASC 410-20, Asset Retirement Obligations, which requires the Company to recognize asset retirement obligations at estimated fair value in the period in which the obligation is incurred. Events that trigger the recognition of asset retirement obligations include land disturbance and construction of properties for which there is a legal obligation to restore the property to its original state. The liability is initially measured at fair value using a discounted cash flow model, and is subsequently adjusted for accretion expense and changes in the amount or timing of the estimated cash flows. A corresponding asset retirement cost is capitalized as part of the carrying amount of the related long-lived assets and is depreciated over the assets’ remaining useful lives.
	Income Taxes
	The Company accounts for income taxes in accordance with Accounting Standard Codification 740, Income Taxes, which requires that deferred tax assets and liabilities be recognized for the tax effect of temporary differences between the financial statement and tax basis of recorded assets and liabilities at enacted statutory tax rates. This guidance also requires that deferred tax assets be reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax assets will not be realized based on both our historical and anticipated earnings levels. The Company reviews its deferred tax assets each reporting period to determine if adjustments to the valuation allowance are necessary.
	The Company records its deferred tax assets and liabilities using enacted tax rates expected to apply to taxable income for the period in which the deferred tax assets or liabilities are expected to be realized. The statutory income tax rates that are applied to the current and deferred income tax calculations differ by the jurisdictions in which the Company conducts business. Changes in such income tax rates and apportionment laws may result in changes in the Company’s deferred income tax assets, liabilities and related expense in the period of enactment.
	Foreign Currency
	The functional currency of the majority of the Company's operations is the U.S. dollar. Assets and liabilities recorded in functional currencies other than U.S. dollars are translated at the spot rate in effect at the applicable reporting date; revenues and expenses in foreign currencies are translated at actual exchange rates for significant transactions or at the average exchange rates in effect during the applicable period. The resulting unrealized cumulative translation adjustment is recorded as a component of "Accumulated other comprehensive income (loss)" in the consolidated balance sheets. The effect of exchange rates on cash balances held in foreign currencies are separately reported in the Company’s consolidated statements of cash flows.
	Transactions denominated in currencies other than the applicable functional currency are recorded based on exchange rates at the time such transactions occur. Changes in exchange rates associated with amounts recorded in the Company’s consolidated balance sheets related to these non-functional currency transactions result in transaction gains and losses that are reflected in "Foreign exchange gains (losses), net" in the consolidated statements of operations and comprehensive income.
	Comprehensive Income (Loss)
	The Company presents comprehensive income (loss) in two separate, but consecutive statements. In addition to Net income (loss), Comprehensive income (loss) includes foreign currency translation adjustments and actuarial gains and losses.
	Earnings (Loss) per Share
	Basic earnings per share is computed by dividing the Company’s net income (loss) attributable to its stockholders, reduced by cumulative undeclared and paid dividends on preferred stock, by the weighted average number of shares of common stock outstanding during the period.
	Diluted earnings per share reflect the dilutive impact of potential common stock and unvested restricted shares of common stock in the weighted average number of common shares outstanding during the period, if dilutive. For this purpose, the “treasury stock method” and “if-converted method,” as applicable, are used. Under the treasury stock method, assumed proceeds upon the exercise of stock options are considered to be used to purchase common stock at the average market price of the shares during the period. Also under the treasury stock method, fixed awards and non-vested shares, such as restricted stock, are deemed options for purposes of computing diluted earnings per share. In applying the if-converted method, conversion is not assumed for purposes of computing diluted earnings per share if the effect would be antidilutive. Convertible preferred stock is antidilutive whenever the amount of the dividend declared in or accumulated for the current period per common share obtainable on conversion, including the deemed dividend in the period from a beneficial conversion feature, exceeds basic earnings per share. Also under the if-converted method, convertible debt is antidilutive whenever its interest per common share obtainable on conversion, including any deemed interest from a beneficial conversion feature and nondiscretionary adjustments, net of tax, exceeds basic earnings per share.
	Research and Development
	Research and development costs, which consist primarily of salaries, outside labor, material and equipment, are expensed as incurred.
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standard Board ("FASB") issued ASU 2013-11, Income Taxes (Topic 740), Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force). Based on this update, an entity is required to present unrecognized tax benefits as a decrease in a net operating loss, similar tax loss or tax credit carryforward if certain criteria are met. The determination of whether a deferred tax asset is available is based on the unrecognized tax benefit and the deferred tax asset that exists at the reporting date and presumes disallowance of the tax position at the reporting date. This guidance will eliminate the diversity in practice in the presentation of unrecognized tax benefits but will not alter the way in which entities assess deferred tax assets for realizability. The amendments are effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2013. The amendments should be applied prospectively to unrecognized tax benefits that exist at the effective date. Early adoption is permitted. The adoption of this updated guidance is not expected to have any material impact on the Company's financial statements and related disclosures.
	In March 2013, the FASB issued ASU 2013-05, Foreign Currency Matters (Topic 830), Parent’s Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (a consensus of the FASB Emerging Issues Task Force). The amendments specify that a cumulative translation adjustment ("CTA") should be released into earnings when an entity ceases to have a controlling financial interest in a subsidiary or group of assets within a consolidated foreign entity and the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For sales of an equity method investment that is a foreign entity, a pro rata portion of CTA attributable to the investment would be recognized in earnings when the investment is sold. When an entity sells either a part or all of its investment in a consolidated foreign entity, CTA would be recognized in earnings only if the sale results in the parent no longer having a controlling financial interest in the foreign entity. In addition, CTA should be recognized in earnings in a business combination achieved in stages (i.e., a step acquisition). The amendments are effective for public companies for fiscal years, and interim periods within those years, beginning after December 15, 2013. The amendments should be applied prospectively to derecognition events occurring after the effective date. Early adoption is permitted. The adoption of this updated guidance is not expected to have any material impact on the Company's financial statements and related disclosures.
	In February 2013, the FASB issued ASU 2013-02, Comprehensive Income (Topic 220), Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This update requires companies to report, in one place, information about reclassifications out of accumulated other comprehensive income ("AOCI"). Companies also are required to present reclassifications by component when reporting changes in AOCI balances. For significant items reclassified out of AOCI to net income in their entirety in the period, companies must report the effect of the reclassifications on the respective line items in the statement where net income is presented. In certain circumstances, this can be done on the face of that statement. Otherwise, it must be presented in the notes. For items not reclassified to net income in their entirety in the period (e.g., pension amounts that are capitalized in inventory), companies must cross-reference in a note to other required disclosures. This update was effective for public companies in fiscal years, and interim periods within those years, beginning after December 15, 2012. The adoption of this updated guidance did not have any impact on the Company's financial statements and related disclosures.
	In July 2012, the FASB issued ASU 2012-02, Intangibles - Goodwill and Other (Topic 350), Testing Indefinite-Lived Intangible Assets for Impairment. In accordance with this update, an entity has the option first to assess qualitative factors to determine whether the existence of events and circumstances indicates that it is more likely than not that the indefinite-lived intangible asset is impaired. If, after assessing the totality of events and circumstances, an entity concludes that it is not more likely than not that the indefinite-lived intangible asset is impaired, then the entity is not required to take further action. However, if an entity concludes otherwise, then it is required to determine the fair value of the indefinite-lived intangible asset and perform the quantitative impairment test by comparing the fair value with the carrying amount and record an impairment charge, if any. This update was effective for annual and interim period impairment tests performed for fiscal years beginning after September 15, 2012. Early adoption was permitted. The adoption of this updated guidance did not have any impact on the Company's financial statements and related disclosures.

Liquidity_and_Capital_Requirem

Liquidity and Capital Requirements	12 Months Ended
	Dec. 31, 2013
Capital Requirements [Abstract]	'
Liquidity and Capital Requirements	'
	Liquidity and Capital Requirements
	The Company expects to use its cash balances of $314.3 million as of December 31, 2013, as well as cash generated from operations, to fund capital expenditures, debt service and other cash requirements. Capital expenditures for the Molycorp Mountain Pass facility are expected to total approximately $65 million in 2014 and $50 million in 2015. Additionally, the Company expects to spend approximately $20 million to $25 million on maintenance and expansion capital expenditures across all other operating segments in 2014. While the Company's cash balances as of December 31, 2013 are expected to be sufficient to satisfy its cash needs throughout 2014, the amount of the Company's cash requirements continues to be dependent on (i) the accuracy of its cost estimates for capital expenditures, (ii) its ability to ramp up run rates at its Molycorp Mountain Pass facility pursuant to its expectations without further delays, and to achieve lower cash costs of production as a result of the commissioning of its chloralkali plant and further optimization of our multi-stage cracking unit, (iii) stable or improved market conditions, (iv) its ability to sell its production of rare earths (including its ability to sell its cerium through market acceptance of SorbX™ or otherwise) and (v) the absence of payments on current and future contingent liabilities. If these assumptions prove inaccurate, the Company's estimates could prove incorrect and it may need additional financing.
	As part of the its cash management procedures, management continues to evaluate opportunities to improve the Company's liquidity, including potential proceeds from revolving credit facilities, and lease and loan financing for certain equipment, although the Company's does not have any firm commitments for such revolving credit facilities.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	The Company's operations are organized into the following four reportable segments: Resources; Chemicals and Oxides; Magnetic Materials and Alloys; and Rare Metals.
	The Resources segment includes the Company's Molycorp Mountain Pass facility where it conducts rare earth minerals extraction to produce: purified unseparated rare earth concentrates; separated rare earth oxides, including lanthanum, cerium and neodymium/praseodymium; heavy rare earth concentrates, which include samarium, europium, gadolinium (“SEG”), terbium, dysprosium, and others; and SorbX™, a line of proprietary rare earth-based water treatment products.
	The Chemicals and Oxides segment includes: the production of rare earths at the Company's operations in Sillamäe, Estonia ("Molycorp Silmet"); heavy rare earth oxides from the Company's facilities in Jiangyin, Jiangsu Province, China; and separated rare earth oxides, salts of REEs, zirconium-based engineered materials and mixed rare earth/zirconium oxides from the Company's facilities in Zibo, Shandong Province, China. Rare earths products and zirconium-based engineered products are primarily supplied to the automotive catalyst, electronics, ceramic, clean technology and glass industries.
	The Magnetic Materials and Alloys segment includes: the production of neodymium-iron-boron ("NdFeB") magnet powders ("Neo Powders™") through wholly-owned manufacturing facilities in Tianjin, China and Korat, Thailand, under the Molycorp Magnequench brand. Neo Powders™ are used to make bonded magnets for a variety of electronic and mechanical products such as micro motors, precision motors, sensors and other applications requiring high levels of magnetic strength, flexibility, small size and reduced weight. This segment also includes manufacturing of neodymium and samarium magnet alloys, other specialty alloy products and rare earth metals at Molycorp Metals and Alloys ("MMA") in Tolleson, Arizona.
	The Rare Metals segment includes the production of gallium, indium, tantalum and rhenium from operations in Quapaw, Oklahoma; Blanding, Utah; Peterborough, Ontario; Sagard, Germany; and Hyeongok Industrial Zone in South Korea. This segment also includes tantalum and niobium from the Company's operations in Sillamäe, Estonia. Rare metals are primarily used in the wireless, light-emitting diode, flat panel display, turbine, solar and catalyst industries. In July 2013, the Company committed to a plan to discontinue operations at its Napanee, Ontario - Canada facility by the end of fiscal 2013 due to a declining demand for rhenium, combined with unfavorable operating costs in this particular recycling sector. Therefore, the operating results of the Napanee facility were included in discontinued operations for the year ended December 31, 2013, and the prior period presentation of financial data for the Rare Metals segment has been revised for comparative purposes. See Note 27 for further details.
	The accounting polices used in the preparation of the segment financial information below are the same as those used in the preparation of the consolidated financial statements. Intersegment sales and transfers are based on prices applicable to similar arms-length transactions with third parties at the time of the sale.
	Year ended December 31, 2012	Resources		Chemicals and Oxides			Magnetic Materials and Alloys			Rare Metals (d)		Corporate and other(a)		Eliminations(b)		Total Molycorp, Inc.
	Revenues:	(In thousands of dollars)
	External	88,870		181,849			179,335			77,642				—		527,696
	Intersegment	7,256		25,717										(32,973	)	—
	Total revenues	96,126		207,566			179,335			77,642				(32,973	)	527,696
	Depreciation, amortization and accretion	(13,991	)	(13,110	)		(19,737	)		(5,837	)	(133	)	—		(52,808	)
	Operating loss (e)	(70,220	)	(191,059	)		(125,543	)		(18,671	)	(85,459	)	24,803		(466,149	)
	Loss before income taxes and equity earnings	(70,469	)	(190,094	)		(126,981	)		(18,181	)	(143,269	)	24,803		(524,191	)
	Total assets at December 31, 2012	1,802,842		639,847			593,197			117,961		575,964		(737,276	)	2,992,535
	Capital expenditures (c)	814,054		10,910			5,614			10,750		1,733		—		843,061
	Year ended December 31, 2011	Resources		Chemicals and Oxides			Magnetic Materials and Alloys			Rare Metals		Corporate and other(a)		Eliminations(b)		Total Molycorp, Inc.
	Revenues:	(In thousands of dollars)
	External	253,563		40,216			56,772			46,280				—		396,831
	Intersegment	55,155		13,902			—			—				(69,057	)	—
	Total revenues	308,718		54,118			56,772			46,280				(69,057	)	396,831
	Depreciation, amortization and accretion	(10,553	)	(1,958	)		(236	)		(2,449	)	(31	)	—		(15,227	)
	Operating income (loss)	218,549		8,700			2,331			2,131		(51,402	)	(27,443	)	152,866
	Income (loss) before income taxes	218,391		5,785			2,336			(634	)	(51,525	)	(27,443	)	146,910
	Total assets at December 31, 2011	824,712		46,368			30,061			71,634		426,080		(143,730	)	1,255,125
	Capital expenditures (c)	401,047		8,170			—			—		—		—		409,217
	(a)	Corporate and other loss before income taxes and equity earnings includes business development costs, personnel costs, stock-based compensation, accounting and legal fees, occupancy expense, information technology costs and interest expense. Total Corporate and other assets is comprised primarily of cash and cash equivalents.
	(b)	The net elimination in operating results includes costs of sales eliminations of $62,343, $57,776 and $41,614 for the years ended December 31, 2013, 2012 and 2011, respectively, which consist of intercompany gross profits as well as eliminations of lower of cost or market adjustments related to intercompany inventory. The total assets elimination is comprised primarily of intercompany investments and intercompany accounts receivable and profits in inventory.
	(c)	On an accrual basis excluding capitalized interest.
	(d)	Excludes operating results from the Napanee facility, which is treated as a discontinued operation for comparative purposes.
	(e)	Includes impairment of goodwill and other long-lived assets in some segments. See notes 7 and 9 below for details.
	The geographic distribution of the Company’s revenues based on customers' locations for the years ended December 31, 2013, 2012 and 2011, was as follows:
		Years Ended December 31,
		2013			2012				2011
		(In thousands)
	Asia:
	China	$	199,021		$	118,086			$	421
	Japan	99,952			160,942				204,262
	Thailand	17,129			7,674				—
	Hong Kong	8,815			4,793				—
	South Korea	12,418			3,828				—
	Singapore	54			212				—
	North America	92,066			103,555				128,544
	Europe	113,549			117,907				56,760
	Other	11,386			10,699				6,844
	Total	$	554,390		$	527,696			$	396,831
	Long-lived tangible assets by geographic location at December 31, 2013 and 2012 were as follows:
		At December 31,
		2013			2012
		(In thousands)
	North America	$	1,627,892		$	1,391,690
	Europe	73,674			75,495
	China	53,131			52,914
	Thailand	6,213			5,902
	Other Asia	1,913			18,221
	Other	51			82
	Total	$	1,762,874		$	1,544,304

Inventory

Inventory	12 Months Ended
	Dec. 31, 2013
Inventory Disclosure [Abstract]	'
Inventory	'
	Inventory
	At December 31, 2013 and 2012, inventory consisted of the following:
		December 31,
		2013		2012
		(In thousands)
	Current:
	Concentrate stockpiles	$	24	$	6,393
	Raw materials	42,627		95,248
	Work in process	41,962		55,229
	Finished goods	65,662		114,903
	Materials and supplies	21,508		15,603
	Total current	$	171,783	$	287,376
	Long-term:
	Concentrate stockpiles	$	4	$	4
	Raw materials	25,325		26,092
	Total long-term	$	25,329	$	26,096
	Assessment of normal production levels
	For the years ended December 31, 2013, 2012 and 2011, the Company determined that $88.1 million, $12.0 million and $4.3 million, respectively, of production costs would have been inventoriable had the Company been operating at normal production levels. These costs were excluded from inventory and included in costs of sales as incurred.
	Write-downs of inventory
	The Company recognized write-downs of $100.3 million, $80.9 million and $2.8 million for the years ended December 31, 2013, 2012 and 2011, respectively, to reduce inventories to the lower of cost or market. The Company also recognized write-downs of stockpile inventory totaling $2.1 million and $2.3 million in 2012 and 2011, respectively, due to adjustments to the estimated REO content.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2013
Deposits [Abstract]	'
Deposits	'
	Deposits
	The Company had $26.0 million and $26.8 million in deposits reported as non-current assets at December 31, 2013 and 2012, respectively, which consisted of the following:
		December 31,
		2013		2012
		(In thousands)
	Escrow arrangement with Kern River Gas Transmission Company ("Kern River")	$	20,612	$	20,612
	Construction insurance program	1,504		1,504
	Collateral placed against the surety bonds issued to California state and regional agencies for the closure and reclamation obligations at the Molycorp Mountain Pass facility, and other deposits	3,881		4,653
	Total	$	25,997	$	26,769

Property_Plant_and_Equipment_n

Property, Plant and Equipment, net	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Property, Plant and Equipment, net	'
	Property, Plant and Equipment, net
	The Company capitalized expenditures of $320.7 million, $902.3 million and $416.7 million for the years ended December 31, 2013, 2012 and 2011, respectively, the majority of which related to the expansion and modernization efforts, and certain other capital projects, at the Molycorp Mountain Pass facility. These amounts include capitalized interest of $71.2 million, $59.3 million and $7.5 million, respectively. Depreciation expense for the years ended December 31, 2013, 2012 and 2011, was $60.3 million, $20.9 million and $14.0 million, respectively. Amortization of assets under capital leases, which started in 2012, was $2.3 million in 2013 and $0.9 million in 2012 and is included with depreciation expense.
	At December 31, 2013 and 2012, property, plant and equipment consisted of the following:
		December 31,
		2013			2012
		(In thousands)
	Land	$	12,822		$	12,475
	Land improvements (15 to 30 years)	327,029			63,269
	Buildings and improvements (4 to 40 years)	418,510			237,379
	Plant and equipment (2 to 15 years)	288,603			194,934
	Vehicles (7 years)	2,986			2,842
	Computer software (5 years)	12,424			9,528
	Furniture and fixtures (5 years)	1,044			1,116
	Construction in progress (a)	755,107			1,011,541
	Natural gas delivery facility under capital lease (10 years)	15,658			15,658
	Mining equipment under capital lease (7 years)	7,370			—
	Mineral properties (Note 8)	23,999			24,327
	Exploration rights (Note 8)	—			16,166
	Property, plant and equipment at cost	1,865,552			1,589,235
	Less accumulated depreciation	(102,678		)	(44,931		)
	Property, plant and equipment, net	$	1,762,874		$	1,544,304
	(a)	Primarily related to expenditures at the Molycorp Mountain Pass facility.
	In 2013 and 2012, the Company recognized impairment charges relating to property and equipment of $16.3 million and $5.9 million, respectively.
	In the fourth quarter of 2013, the Company identified certain equipment in the Resources segment that was no longer in use or related to expansion projects that have been placed on hold indefinitely. Those assets had a net book value of approximately $14.2 million and were written off with a related charge included in "Impairment of goodwill and other long-lived assets" in the consolidated statement of operations and comprehensive income. The remaining impairment charges recognized in 2013 related to obsolete assets identified in other segments.
	In the fourth quarter of 2012 the Company recognized impairment charges for equipment totaling $3.8 million at the Resources segment and $2.0 million at the Molycorp Silmet facility (Rare Metals segment).

Mineral_Properties_Development

Mineral Properties, Development Costs and Exploration Rights	12 Months Ended
	Dec. 31, 2013
Extractive Industries [Abstract]	'
Mineral Properties, Development Costs and Exploration Rights	'
	Mineral Properties, Development Costs and Exploration Rights
	Mineral properties and development costs, which are referred to collectively as mineral properties, include acquisition costs, drilling costs, and the cost of other development work associated with the Molycorp Mountain Pass facility, all of which are capitalized. The Company began depleting mineral properties in 2012 using the units of production method over estimated proven and probable reserves.
	Exploration rights represent rights acquired to explore properties that are believed to contain mineral deposits. During the fourth quarter of 2012, the Company completed the acquisition of exploration rights for total consideration of $16.2 million, consisting of 788,410 shares of the Company's common stock at $10.147 per share and a cash payment of $8.2 million. At December 31, 2013, the Company determined that the underlying mineral deposits could not be economically extracted and wrote-off the related $16.2 million carrying value, with a related charge included in "Impairment of goodwill and other long-lived assets" in the consolidated statement of operations and comprehensive income.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Other Intangible Assets	'
		Goodwill and Intangible Assets
	Goodwill
	The Company tested the recoverability of its goodwill at December 31, 2013 and 2012. For purposes of this analysis, the Company determined that: the Resources segment, which has no goodwill, constitutes a reporting unit; the Molycorp Silmet facility, which is included in the Chemicals and Oxides segment in relation to the production of rare earths and in the Rare Metals segment in relation to the manufacturing of tantalum and niobium, constitutes a reporting unit; the MMA facility, which is part of the Magnetic Materials and Alloys segment, constituted a reporting unit in 2012, but it was integrated in the Magnetic Materials and Alloys segment in 2013; the Chemicals and Oxides segment, exclusive of the production of rare earths from the Molycorp Silmet facility, constitutes a reporting unit; and the Rare Metals segment, exclusive of both tantalum and niobium production from the Molycorp Silmet facility and the Buss & Buss facility, which are individual reporting units, constitutes a reporting unit.
	At December 31, 2013, the Company concluded that the fair value of the Chemicals and Oxides segment and the Molycorp Silmet facility exceeded their respective carrying values; the fair value of the Magnetic Materials and Alloys segment approximated its carrying value; the Rare Metals segment, excluding the Buss & Buss facility, had a fair value in excess of its carrying value, but the Buss & Buss facility's fair value was less than its carrying value. As a result, the Company performed an additional step to determine the implied fair value of the Buss & Buss facility's goodwill and recognized an impairment charge of approximately $11.0 million in the Rare Metals segment to account for the excess of such implied goodwill over its carrying value. The main factors leading to this impairment charge included reduced cash flows projections for the Buss & Buss business combined with an increase in the reporting unit's working capital, which stemmed, primarily, from the revaluation of its inventory.
	At December 31, 2012, the Company concluded that the Molycorp Silmet facility's fair value exceeded its carrying value; however, for the other reporting units that included goodwill, the estimated fair value did not exceed their respective carrying values. As a result, the Company completed step two of the impairment test and determined that the certain goodwill was impaired for the Chemicals and Oxides, Magnetic Materials and Alloys and Rare Metals segments. The Company initially recorded a goodwill impairment charge of approximately $258.3 million that was primarily associated with the reporting units created as a result of the Molycorp Canada acquisition. Inputs used to fair value the Company's reporting units are considered Level 3 inputs of the fair value hierarchy.
	In connection with the final allocation of the consideration transferred as a result of the Molycorp Canada acquisition, which was completed in the second quarter of 2013, the Company increased the initial carrying amount of goodwill by $31.6 million, but recognized an immediate offsetting impairment charge of $31.6 million that completely offset the incremental goodwill. This additional goodwill impairment was recognized retroactively in the fourth quarter of 2012.
	Circumstances that negatively affected the Company's estimate of fair value of its reporting units in 2012 included: the depressed pricing environment for certain rare earths and rare metals, delays in the development of products by the Company's customers that utilize rare earths and rare metals, and delays in ramping up the Molycorp Mountain Pass facility, which impaired the Company's ability to enter into longer-term contracts and generate the anticipated synergies expected from the Molycorp Canada acquisition.
	Changes in the carrying value of goodwill by reportable segment during the years ended December 31, 2013, 2012 and 2011, were as follows:
		Chemicals and Oxides				Magnetic Materials and Alloys				Rare Metals				Total
		(In thousands)
	31-Dec-10	$	—			$	—			$	—			$	—
	Goodwill acquired	728				1,977				727				3,432
	31-Dec-11	728				1,977				727				3,432
	Goodwill acquired	285,633				213,525				27,046				526,204
	Impairment	(161,132		)		(112,694		)		(16,068		)		(289,894		)
	31-Dec-12	125,229				102,808				11,705				239,742
	Impairment	—				—				(10,992		)		(10,992		)
	31-Dec-13	$	125,229			$	102,808			$	713			$	228,750
	The increase in goodwill in 2012 related to the acquisition of Molycorp Canada. The increase in goodwill in the Chemicals and Oxides and Rare Metals segments in 2011 related to the acquisition of Molycorp Silmet, while the increase in the Magnetic Materials and Alloys segment related to the MMA acquisition.
	Intangible Assets
	At December 31, 2013 and 2012, intangible assets consisted of the following:
		Customer relationships			Rare earths quotas			Patents			Trade names			Land use rights			Other		Total
	Gross carrying amount	(In thousands)
	31-Dec-12	$	344,774		$	78,300		$	33,252		$	15,586		$	3,568		$	4,420	$	479,900
	Additions	48			—			—			—			—			—		48
	Foreign currency translation adjustment	(242		)	—			—			—			—			—		(242		)
	Impairment	—			(78,300		)	(33,100		)	—			—			—		(111,400		)
	31-Dec-13	$	344,580		$	—		$	152		$	15,586		$	3,568		$	4,420	$	368,306
	Accumulated Amortization
	31-Dec-12	$	14,095		$	4,035		$	9,365		$	1,152		$	66		$	249	$	28,962
	Amortization	22,145			7,018			13,554			65			161			613		43,556
	Adjustments	(260		)	—			—			(874		)	—			—		(1,134		)
	Impairment	—			(11,053		)	(22,892		)	—			—			—		(33,945		)
	31-Dec-13	35,980			—			27			343			227			862		37,439
	Net book value	$	308,600		$	—		$	125		$	15,243		$	3,341		$	3,558	$	330,867
		Customer relationships			Rare earths quotas			Patents			Trade names			Land use rights			Other		Total
	Gross carrying amount	(In thousands)
	31-Dec-11	$	2,669		$	—		$	—		$	786		$	—		$	—	$	3,455
	Additions	342,105			78,300			39,252			14,800			3,568			4,420		482,445
	Impairment	—			—			(6,000		)	—			—			—		(6,000		)
	31-Dec-12	$	344,774		$	78,300		$	33,252		$	15,586		$	3,568		$	4,420	$	479,900
	Accumulated Amortization
	31-Dec-11	$	170		$	—		$	—		$	213		$	—		$	—	$	383
	Amortization	13,925			4,035			9,365			939			66			249		28,579
	31-Dec-12	14,095			4,035			9,365			1,152			66			249		28,962
	Net book value	$	330,679		$	74,265		$	23,887		$	14,434		$	3,502		$	4,171	$	450,938
	In December 2013, the Company determined there was no longer value associated with its Chinese rare earths export quotas because the Chinese government had recently turned to other means for controlling its domestic rare earth industry and, therefore, the Company's Zibo and Jiangyin facilities in the Chemicals and Oxides segment would no longer be able to benefit from the related export premiums. As a result, the Company recognized a charge of $67.2 million for the rare earths quotas. Additionally, the Company recorded a charge of $10.2 million to write-off a patent in the Magnetic Materials and Alloys segment due to updated forecast of margins on products produced using this patent that is scheduled to expire in 2014. Both impairment charges described above were included in "Impairment of goodwill and other long-lived assets" in the consolidated statement of operations and comprehensive income.
	The increases in intangible assets in 2012 were associated with the Molycorp Canada acquisition. In the fourth quarter of 2012, the Company recorded a $6.0 million impairment charge relating to certain patents in the Magnetic Materials and Alloys segment due to updated lower forecast of margins on products produced using patents that were scheduled to expire in 2014. The trade names acquired in 2012 are the Company's only indefinite-lived intangible assets.
	Amortization expense on intangible assets in 2011 was $0.2 million. Amortization expense for the next five years and thereafter is expected to be as follows:
		(In thousands)
	2014	$	23,816
	2015	23,789
	2016	23,740
	2017	23,740
	2018	23,576
	Thereafter	197,406

Investments

Investments	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investments	'
	Investments
	The following table provides a reconciliation of the carrying value of the Company's investments at December 31, 2013 and 2012:
		Investment at cost			Equity Method Investments
		Boulder Wind Power, Inc.			IMJ			Keli			Ingal Stade			Other investments at cost				Total
		(In thousands)
	31-Dec-11	$	20,000		$	—		$	—		$	—		$	—			$	20,000
	Additions	—			27,598			12,200			4,900			2,828				47,526
	Equity loss	n/a			(2,405		)	(1,200		)	115			n/a				(3,490		)
	31-Dec-12	20,000			25,193			11,000			5,015			2,828				64,036
	Additions	—			3,419			—			—			—				3,419
	Equity loss	n/a			(6,529		)	(2,600		)	(40		)	n/a				(9,169		)
	Impairment	(8,000		)	—			—			—			(1,411		)	(a)	(9,411		)
	31-Dec-13	$	12,000		$	22,083		$	8,400		$	4,975		$	1,417			$	48,875
	(a) The impairment charge in 2013 relates to the equity interest in Atlantic Metals & Alloys, LLC.
	Boulder Wind Power, Inc.
	On September 13, 2011, the Company invested $20.0 million into Boulder Wind Power, Inc. Series B convertible preferred stock, which is accounted for at cost. At December 31, 2013, the Company reassessed the carrying value of this investment and determined that it should be written down to $12.0 million. The estimated valuation, resulting in an impairment charge of $8.0 million recognized in "Other (expense) income" in the consolidated statement of operations and comprehensive income, was based on a market approach using Level 3 inputs in the fair value hierarchy based on management’s judgment.
	Intermetallics Japan Joint Venture ("IMJ")
	In January 2012, Molycorp, Daido Steel Co., Ltd. (“Daido”) and Mitsubishi Corporation (“Mitsubishi”) entered into a definitive shareholders agreement for the purpose of funding IMJ to manufacture sintered NdFeB permanent rare earth magnets. The capital contribution ratio of IMJ is 30.0% by Molycorp, 35.5% by Daido and 34.5% by Mitsubishi. During the first quarter of 2013, Molycorp contributed $3.4 million in cash to complete the acquisition of its proportional ownership in IMJ. Total contributions by Molycorp to IMJ from the signing of the definitive shareholders agreement were $31.0 million. Molycorp accounts for this investment under the equity method because it has the ability to exercise significant influence over the operating and financial policies of IMJ, as evidenced by Molycorp’s ownership share and its proportional voting rights and representation in the Board of Directors of IMJ.
	Ganzhou Keli Rare Earth New Material Co., Ltd. (“Keli”)
	The Company acquired a 25% equity interest in Keli for $12.2 million on June 11, 2012. Keli is a Chinese business that converts REO into metals for use in Neo Powders™.
	Ingal Stade GmbH (“Ingal Stade”)
	On June 11, 2012, the Company acquired a 50% ownership interest in Ingal Stade for $4.9 million, a German joint venture involved in the extraction of gallium metal from alumina smelter bayer liquor with purity level of 5N (99.999%) or higher.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	Molycorp Canada
	On June 11, 2012, Molycorp completed the acquisition of all of the outstanding equity of Molycorp Canada's predecessor company pursuant to the terms of an arrangement agreement (the "Arrangement Agreement") for an aggregate purchase price of approximately $1,192.3 million. Pursuant to the Arrangement Agreement, Molycorp Canada's former shareholders elected to receive: (a) cash consideration equal to Canadian dollars ("Cdn") $11.30 per share of Molycorp Canada's predecessor company's common stock; or (b) share consideration of 0.4242 shares of Molycorp common stock or 0.4242 shares (the "Exchangeable Shares") issued by MCP Exchangeco Inc., Molycorp's wholly-owned Canadian subsidiary, which are exchangeable for shares of Molycorp's common stock on a one for one basis, per each share of Molycorp Canada's predecessor company's common stock; or (c) a combination of cash and shares of Molycorp common stock or Exchangeable Shares, all subject to the proration mechanics set forth in the Arrangement Agreement.
	The consideration paid to Molycorp Canada's former shareholders was comprised of approximately $908.2 million in cash, exclusive of realized losses on the contingent forward contract to purchase $870.0 million Canadian dollars, accounted for as a separate transaction apart from the business combination, as further discussed in Note 24. Additionally, 13,545,426 shares of Molycorp common stock and 507,203 Exchangeable Shares were issued and collectively valued at $284.1 million based on the closing price of the Company's common stock on the acquisition date in accordance with the relevant accounting guidance. The Exchangeable Shares have no par value.
	A preliminary allocation of the consideration transferred to the net assets of Molycorp Canada was made as of June 11, 2012. During the second quarter of 2013, the Company further adjusted the preliminary values assigned to certain assets and liabilities of Molycorp Canada in order to reflect additional information obtained since June 11, 2012. As a result of the additional goodwill recognized during the final allocation of the consideration transferred to the net assets of Molycorp Canada, the goodwill impairment the Company recognized in the fourth quarter of 2012 has increased by $31.6 million to $287.9 million. The measurement period adjustments described in the table below have been reflected in the opening balance sheet; however, since these adjustments did not have a significant impact on the Company's consolidated statements of operations and comprehensive income or cash flows in any period, those statements were not retrospectively adjusted.
	The following table summarizes the purchase consideration as well as the estimated fair value of the assets acquired and liabilities assumed in the Molycorp Canada acquisition:
		Preliminary Allocation of Consideration Transferred as of December 31, 2012			Measurement Period Adjustments			Final Allocation of Consideration Transferred
	Purchase consideration:	(In thousands)
	Cash consideration	$	908,181					$	908,181
	Fair value of Molycorp common stock and Exchangeable Shares issued	284,144						284,144
	Total purchase consideration	$	1,192,325					$	1,192,325
	Estimated fair values of the assets and liabilities acquired:
	Cash and cash equivalents	$	317,169		$	—		$	317,169
	Restricted cash	4,951			—			4,951
	Accounts receivable	101,470			—			101,470
	Inventory	250,989			—			250,989
	Prepaid expenses and other current assets	26,893			—			26,893
	Property, plant and equipment	75,745			—			75,745
	Investments	21,019			(1,091		)	19,928
	Intangibles	482,234			—			482,234
	Deferred tax charges	13,435			—			13,435
	Deferred tax assets	11,473			(1,423		)	10,050
	Goodwill	494,809			31,616			526,425
	Other non-current assets	4,367			—			4,367
	Accounts payable and accrued expenses	(138,576		)	—			(138,576		)
	Debt	(255,338		)	—			(255,338		)
	Other current liabilities	(33,990		)	—			(33,990		)
	Deferred tax liabilities	(154,309		)	5,880			(148,429		)
	Other non-current liabilities	(14,255		)	—			(14,255		)
	Non-controlling interests	(15,761		)	(34,982		)	(50,743		)
	Total purchase consideration	$	1,192,325		$	—		$	1,192,325
	Goodwill associated with the Molycorp Canada acquisition arose primarily because of Molycorp Canada's proven leadership in the development, processing, and distribution of technically advanced rare earth products; greater exposure to the world’s largest and fastest-growing rare earths consuming market, China; deferred tax liabilities; and expected synergies that do not qualify for separate recognition. The goodwill is not amortized and is not deductible for tax purposes.
	The following unaudited pro forma financial information provides what the Company's consolidated revenues, net income (loss) and basic earnings per share would have been had the acquisition closed on January 1, 2011:
	(In thousands, except per share amounts)	Revenues				Net income (loss)				Net income (loss)			EPS Basic
										attributable to Molycorp
	Unaudited pro forma January 1, 2012 to December 31, 2012 (combined entity)	$	863,728			$	(463,716	)		$	(473,249	)	$	(4.53	)
	Unaudited pro forma January 1, 2011 to December 31, 2011 (combined entity)	$	1,196,876			$	241,903			$	231,772		$	2.66
	The unaudited pro forma revenues, earnings and earnings per share amounts have been adjusted to: a) eliminate the effect of sales and costs that occurred previous to the business combination between the Company and Molycorp Canada; b) reflect the incremental depreciation and amortization expense as a result of the allocation of the purchase price to certain depreciable and amortizable assets with useful lives ranging from two to 30 years; c) the tax effect of unaudited pro forma adjustments using Molycorp's federal, state and international statutory tax rates based on the applicable tax jurisdictions; and d) the estimated increase in interest expense associated with the issuance of the Company's Senior Notes (as defined below) the proceeds from which were used to finance a portion of the purchase consideration. The unaudited pro forma earnings of the combined entity for the year ended December 31, 2012 were also adjusted to exclude $115.2 million of non-recurring costs. The weighted average number of shares outstanding utilized in the basic income (loss) per share calculations have been adjusted to reflect the common shares issued to Molibdenos y Metales S.A. ("Molymet") the proceeds from which were used to finance a portion of the purchase consideration.
	For the year ended December 31, 2012, the Company recognized approximately $62.0 million of transaction costs related to the Molycorp Canada acquisition in the consolidated statement of operations and comprehensive income as follows:
		(In thousands)
	Corporate development
	Legal, accounting and advisory fees	$	16,498
	Other expenses:
	Contingent forward contract loss	$	37,589
	Interest expense:
	Bridge loan fee	$	7,937
	Increase of Equity Interest in JAMR
	During the fourth quarter of 2012, the Company acquired an additional 5% of its majority owned Jiangyin Jia Hua Advanced Material Resources Co. Ltd. ("JAMR") bringing its equity interest in JAMR to 95%. The investment in JAMR originally was part of the Molycorp Canada acquisition. The purchase price for the additional equity interest in JAMR was $15.0 million, of which $5.4 million was paid in cash on the date of closing and the remaining $9.6 million, plus accrued interest of $0.2 million, which was paid in cash at end of 2013.
	Molycorp Silmet and MMA
	The following table summarizes purchase consideration as well as the estimated fair value of the assets acquired and liabilities assumed for the acquisition of 90.023% controlling interest in Molycorp Silmet on April 1, 2011 and of MMA on April 15, 2011 (in thousands):
	(In thousands)	Molycorp Silmet				MMA
		April 1, 2011				April 15, 2011
	Purchase consideration:
	Cash consideration	$	9,021			$	17,500
	Fair value of Molycorp common stock issued	72,653				—
	Total purchase consideration	$	81,674			$	17,500
	Fair values of the assets and liabilities acquired:
	Cash	$	105			$	6,395
	Accounts receivable and other current assets	8,626				5,474
	Inventory	37,404				11,327
	Property, plant and equipment, net	63,393				4,512
	Intangible assets subject to amortization	2,669				—
	Goodwill	1,455				1,977
Liabilities	(19,974		)		(8,989		)
Deferred tax liabilities	—				(3,196		)
Long-term debt	(3,184		)		—
Noncontrolling interest	(8,820		)		—
Total purchase consideration	$	81,674			$	17,500
Goodwill associated with the Molycorp Silmet acquisition arose primarily because of the acquired workforce. Goodwill associated with the MMA acquisition arose primarily because of the requirement to record a deferred tax liability for the difference between the assigned values and the tax bases of assets acquired and liabilities assumed. The fair value of the noncontrolling interest in Molycorp Silmet as of April 1, 2011 was valued using a combination of the market approach and income approach. As a result of its annual impairment test, the Company wrote-off the goodwill related to the MMA acquisition as of December 31, 2012.
The following unaudited pro forma financial information provides what the Company's consolidated revenues, net income (loss) and basic earnings per share would have been had the acquisition closed on January 1, 2011:
(In thousands, except per share amounts)	Revenues				Net income				Net income			EPS Basic
									attributable to
									Molycorp
Unaudited pro forma January 1, 2011 to December 31, 2011 (combined entity)	$	430,305			$	105,397			$	104,590		$	1.13
The unaudited pro forma amounts are not necessarily indicative of the operating results that would have occurred if these acquisitions had taken place on January 1, 2011. The 2011 earnings of the combined entity were adjusted to exclude $69.1 million of intercompany sales, $28.0 million of intercompany earnings and $2.1 million of non-recurring acquisition-related costs the Company incurred to acquire Molycorp Silmet and MMA, and to reverse $1.1 million of purchase price variance MMA capitalized during the first quarter of 2011.
Molycorp Silmet
On April 1, 2011, Molycorp acquired 80% of the outstanding shares of Molycorp Silmet from AS Silmet Grupp in exchange for 1,593,419 shares of Molycorp common stock contractually valued at $80.0 million based on the average closing price of the Company’s common stock as reported by The New York Stock Exchange for the 20 consecutive trading days immediately preceding April 1, 2011, the acquisition date.
Generally, the acquisition-date fair value of shares of common stock transferred by the acquirer is the closing price of that stock on the same date adjusted by a discount that a market participant would require as a result of any restrictions on the sale or transferability of the stock. The fair value of common stock of $72.7 million disclosed in the table above is based on the closing price of the Company’s common stock on the acquisition date, net of an estimated discount of 23% that a market participant would require given that issuance of the shares of common stock Molycorp transferred in consideration to AS Silmet Grupp was not registered under the Securities Act of 1933 (the "Securities Act") and such shares were subject to certain lock-up provisions, which limited AS Silmet Grupp’s ability to sell these shares. AS Silmet Grupp retained a 9.977% ownership interest in Molycorp Silmet on the acquisition date; Molycorp acquired the other 10.023% from Treibacher Industrie AG for $9.0 million in cash also on April 1, 2011.
On October 24, 2011, the Company acquired the remaining 9.977% ownership interest in Molycorp Silmet for $10.0 million in cash, which resulted in an adjustment to Additional Paid-In Capital of $0.4 million for the difference between the consideration paid and the carrying value of the noncontrolling interest at October 24, 2011.
The Molycorp Silmet acquisition provided Molycorp with a European base of operations and increased the Company’s yearly REO production capacity by approximately 3,000 mt. Molycorp Silmet sources a portion of rare earth feed stocks for production of its products primarily from the Molycorp Mountain Pass facility. The main focus of Molycorp Silmet is on the production of REO and metals, including didymium metal, a critical component in the manufacture of NdFeB permanent rare earth magnets. Molycorp Silmet’s manufacturing operation is located in Sillamäe, Estonia.
MMA
On April 15, 2011, Molycorp completed the acquisition from Santoku Corporation (“Santoku”) of all the issued and outstanding shares of capital stock of MMA in an all-cash transaction for $17.5 million. The acquisition provided Molycorp with access to certain intellectual property relative to the development, processing and manufacturing of neodymium and samarium magnet alloy products. As part of the stock purchase agreement, Santoku will provide consulting services to Molycorp for the purpose of maintaining and enhancing the quality of MMA’s products. Molycorp and Santoku also entered into five-year marketing and distribution agreements for the sale and distribution of neodymium and samarium magnet alloy products produced by each party. Additionally, the parties entered into a rare earth products purchase and supply agreement through which MMA will supply Santoku with certain rare earth alloys for a two-year period at prices equal to the feedstock cost plus the applicable product premium as such terms are defined in the agreement.

Accrued_Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2013
Payables and Accruals [Abstract]	'
Accrued Expenses	'
	Accrued Expenses
	Accrued expenses at December 31, 2013 and 2012 consisted of the following:
		December 31,
		2013		2012
		(In thousands)
	Defined contribution plan	$	1,921	$	1,400
	Professional fees	135		4,971
	Accrued payroll and related benefits	5,739		7,532
	Sales and use tax	3,354		7,187
	Bonus accrual	4,449		3,503
	Interest payable	18,158		15,253
	Advance from customer	600		1,753
	Withholding taxes	2,563		2,929
	Amount payable to noncontrolling interest	352		9,640
	Other accrued expenses	11,230		4,845
	Total accrued expenses	$	48,501	$	59,013

Asset_Retirement_Obligation

Asset Retirement Obligation	12 Months Ended
	Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligation	'
	Asset Retirement Obligation
	The following table presents the activity in the Company’s asset retirement obligation ("ARO") for the years ended December 31, 2013 and 2012:
		December 31,
		2013			2012
		(In thousands)
	Balance at beginning of period	$	22,125		$	15,541
	Obligations settled	(3,849		)	(2,954		)
	Accretion expense	1,328			1,299
	Revisions in estimated cash flows	(3,793		)	7,872
	Loss on settlement	1,772			367
	Balance at end of period	$	17,583		$	22,125
	The balances above for the years ended December 31, 2013 and 2012 include a short-term portion of $0.6 million and $3.5 million, respectively, which were recorded under other current liabilities. Depreciation expense associated with the ARO was $2.5 million, $2.0 million and $1.0 million in 2013, 2012 and 2011, respectively.
	In the fourth quarter of 2013, the Company updated the timing of the closure plan for the Molycorp Mountain Pass facility from 2035 to 2042. In addition, the Company updated the timing of certain reclamation efforts. As a result of these changes, the Company reduced its ARO by $3.8 million.
	As part of the transition of the Molycorp Mountain Pass operations from the legacy facilities to the new facilities, the Company determined that a portion of the ore deposit was located beneath a legacy flotation plant. To facilitate the expansion of the mine, the Company substantially demolished that plant in 2013 and incurred costs in excess of its original estimate that led to a large portion of the settlement loss of $1.8 million recognized in 2013. Demolition of the legacy flotation plant is expected to be completed by the first quarter of 2014.
	During 2012, the Company increased its ARO by approximately $7.9 million, including $3.8 million related to the addition of new processing facilities at the Molycorp Mountain Pass facility and $4.1 million related to revised estimates for the demolition and reclamation of the old mill and mineral recovery areas at the facility.
	The Company is required to provide the applicable governmental agencies with financial assurances relating to its closure and reclamation obligations. At December 31, 2013, the Company had financial assurance requirements of $28.8 million, which were satisfied with surety bonds placed with California state and regional agencies.

Debt_and_Capital_Lease_Obligat

Debt and Capital Lease Obligations	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Debt and Capital Lease Obligations	'
	Debt and Capital Lease Obligations
	The following tables provide a summary of the current and non-current portions of the debt outstanding at December 31, 2013 and 2012:
		December 31,
		2013							2012
		Current				Non-Current			Current				Non-Current
		(In thousands)
	Bank loans due May 2014 - September 2017	$	14,128			$	2,699		$	39,252			$	4,118
	3.25% Convertible Notes, net of discount, due June 2016	—				207,028			—				198,689
	6.00% Convertible Notes, net of discount, due September 2017	—				346,708			—				331,977
	5.00% Debentures, net of discount, due December 2017	—				2,493			—				2,774
	5.50% Convertible Notes, net of discount, due February 2018	—				148,198			—				—
	10% Senior Secured Notes, net of discount, due June 2020	—				637,435			—				636,111
	Total debt	14,128				1,344,561			39,252				1,173,669
	Capital lease obligations	2,234				19,355			352				15,163
	Total debt and capital lease obligations	$	16,362			$	1,363,916		$	39,604			$	1,188,832
	Weighted average interest rate on the bank loans was 3.59% and 3.57% at December 31, 2013 and 2012, respectively. The total amount of unused lines of credit was $23.7 million at December 31, 2013.
	Scheduled minimum debt repayments, excluding capital lease obligations, are $14.1 million in 2014, $1.5 million in 2015, $230.9 million in 2016, $414.4 million in 2017, $175.0 million in 2018 and $650.0 million thereafter.
		3.25% Convertible Notes						6.00% Convertible Notes							5.50% Convertible Notes				10% Senior Notes
		At December 31,
		2013			2012			2013			2012				2013			2012	2013			2012
		(In thousands)
	Principal amount	$	230,000		$	230,000		$	414,000		$	414,000			$	172,500		n/a	$	650,000		$	650,000
	Unamortized debt discount	(22,972		)	(31,311		)	(67,292		)	(82,023		)		(24,302		)	n/a	(12,565		)	(13,889		)
	Net carrying amount	$	207,028		$	198,689		$	346,708		$	331,977			$	148,198		n/a	$	637,435		$	636,111
	Interest cost (a)	$	15,839		$	15,312		$	39,779		$	17,457			$	13,107		n/a	$	66,323		$	40,070
	(a) Interest cost includes the coupon interest, accretion of the initial equity component of the convertible notes described below (3.25% - $36,227; 6.00% - $68,695; and 5.50% - $21,815), accretion of the underwriting discounts and amortization of the issuance costs allocated to the liability component.
	2013 Debt Issuance
	On January 30, 2013, the Company issued $150.0 million aggregate principal amount of its 5.50% Convertible Senior Notes due 2018 (the “5.50% Convertible Notes”) in a registered public offering. Certain officers, directors and other related parties of the Company purchased $20.5 million of this aggregate principal amount. On March 1, 2013, the underwriters of such offering purchased an additional $22.5 million aggregate principal amount of the 5.50% Convertible Notes. After deducting the underwriting discounts and commissions, net proceeds from the issuance of the 5.50% Convertible Notes were $165.6 million.
	The 5.50% Convertible Notes are Molycorp's senior unsecured obligations and pay a 5.50% interest semi-annually in arrears on February 1 and August 1 of each year, commencing on August 1, 2013. The 5.50% Convertible Notes are convertible at any time into shares of Molycorp's common stock, cash, or a combination thereof, at Molycorp's election. The conversion rate will initially be 138.8889 shares of Molycorp common stock per $1,000 principal amount of notes (equivalent to an initial conversion price of approximately $7.20 per share of Molycorp's common stock), subject to customary adjustments. The 5.50% Convertible Notes will mature on February 1, 2018, unless earlier repurchased, redeemed or converted in accordance with their terms prior to that date. Molycorp will have the right to redeem the 5.50% Convertible Notes on or after February 1, 2016 if the last reported sale price of its common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period. The 5.50% Convertible Notes rank equal in right of payment to existing and future liabilities that are not expressly subordinated to the 5.50% Convertible Notes, and rank effectively junior to Molycorp's existing and future secured indebtedness.
	The Company separately accounts for the liability and equity components of convertible debt instruments, such as the 5.50% Convertible Notes, that may be settled entirely or partially in cash upon conversion in a manner that reflects the Company's economic interest cost. The additional discount on the liability component is amortized to interest cost over the term of the 5.50% Convertible Notes. The equity component of $21.8 million is included in additional paid-in capital in the consolidated balance sheet and is treated as original issue discount for purposes of accounting for the liability component. Transaction costs related to the issuance of the 5.50% Convertible Notes have been allocated to the liability and equity components in proportion to the allocation of proceeds to the components, and accounted for as debt issuance costs (recognized as interest expense over the life of the 5.50% Convertible Notes using the effective interest method) and equity issuance costs (charged against equity), respectively.
	2012 Debt Issuances and Assumed Liabilities
	6.00% Convertible Notes
	On August 22, 2012, the Company issued $360.0 million aggregate principal amount of its 6.00% Convertible Senior Notes due 2017 (the “6.00% Convertible Notes”) in a registered public offering. On August 28, 2012, the underwriters of the 6.00% Convertible Notes exercised their option to purchase an additional $54.0 million aggregate principal amount of the 6.00% Convertible Notes. Total net proceeds from the issuance of the 6.00% Convertible Notes were $395.7 million, after deducting the underwriting discounts and commissions. Certain of the Company's directors, officers and other related parties purchased $6.4 million of the aggregate principal amount of the 6.00% Convertible Notes, for which the Company did not pay any underwriting discounts and commissions.
	The 6.00% Convertible Notes are Molycorp's senior unsecured obligations with interest payable semi-annually in arrears on March 1 and September 1 of each year, commencing on March 1, 2013. The 6.00% Convertible Notes will mature on September 1, 2017, unless earlier repurchased, redeemed or converted in accordance with their terms, and will be convertible at any time prior to the second scheduled trading day immediately preceding the maturity date into shares of common stock, cash, or a combination thereof, at Molycorp's election. The conversion rate will initially be 83.333 shares of common stock per $1,000 principal amount of 6.00% Convertible Notes (equivalent to an initial conversion price of approximately $12 per share of common stock), subject to customary adjustments. Molycorp will have the right to redeem the 6.00% Convertible Notes on or after September 1, 2015 if the last reported sale price of its common stock has been at least 130% of the conversion price then in effect for at least 20 trading days during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which Molycorp provides notice of redemption at a redemption price equal to 100% of the principal amount of the 6.00% Convertible Notes to be redeemed, plus accrued and unpaid interest. The 6.00% Convertible Notes rank equal in right of payment to existing and future liabilities that are not expressly subordinated to the 6.00% Convertible Notes, and rank effectively junior to Molycorp's existing and future secured indebtedness.
	The Company separately accounts for the liability and equity components of convertible debt instruments, such as the 6.00% Convertible Notes, that may be settled entirely or partially in cash upon conversion in a manner that reflects the Company's economic interest cost. The additional discount on the liability component is amortized to interest cost over the term of the 6.00% Convertible Notes. The equity component of $68.7 million is included in additional paid-in in the consolidated balance sheet and is treated as original issue discount for purposes of accounting for the liability component. Transaction costs related to the issuance of the 6.00% Convertible Notes have been allocated to the liability and equity components in proportion to the allocation of proceeds to the components, and accounted for as debt issuance costs and equity issuance costs, respectively.
	5.00% Debentures
	As a result of the Molycorp Canada acquisition, the Company assumed $230.0 million principal amount of subordinated unsecured convertible debentures of the predecessor of Molycorp Canada due December 2017 (the “Debentures”) maturing on December 31, 2017. The Debentures bear interest at 5.00% per annum and are convertible at $13.80 per share of Molycorp Canada's predecessor company. As required under the change of control provisions contained in the original underlying indenture, holders of the Debentures had the option to either require the Company to repurchase the Debentures at par plus accrued interest, convert the Debentures into common shares of Molycorp Canada's predecessor company, including a number of additional “make-whole” shares, or hold the Debentures to maturity. In August 2012, holders of $9.4 million aggregate principal amount of Debentures elected to convert, while holders of $217.9 million aggregate principal amount of Debentures elected to early redeem their Debentures for cash plus accrued interest. Under the term of the indenture governing the Debentures, as amended at the time of the Molycorp Canada acquisition, the holders of the Debentures that converted received, at their election and in lieu of receiving shares of Molycorp Canada's predecessor company, the same cash and/or share consideration that was paid to Molycorp Canada's former shareholders in connection with the acquisition of Molycorp Canada, subject to the same pro-ration calculation, as if such holders had converted immediately prior to the acquisition. As a result of the conversion in August 2012, a total of $8.0 million, including accrued interest, was paid in cash with the remainder converted into 99,723 shares of Molycorp common stock.
	In 2013, holders of $0.3 million aggregate principal amount of the Debentures elected to convert their notes at the same pro-ration of cash and shares consideration as if such holders had converted immediately prior to the acquisition of Molycorp Canada. For the Debentures converted in 2013, the Company paid a total of $0.2 million, including accrued interest, in cash with the remainder converted into 2,471 shares of Molycorp common stock.
	10% Senior Notes
	On May 25, 2012, Molycorp issued $650.0 million aggregate principal amount of senior secured notes due 2020 (the "Senior Notes") in an offering that was exempt from the registration requirements of the Securities Act. Total net proceeds from the issuance of the Senior Notes were $635.4 million after deducting the initial purchasers' discounts. The Senior Notes bear interest at the rate of 10% per year payable on June 1 and December 1 of each year beginning on December 1, 2012. At any time and from time to time prior to June 1, 2016, the Company may redeem any of the Senior Notes at a price equal to 100% of the principal amount thereof plus an applicable make-whole premium and accrued and unpaid interest. At any time and from time to time from and after June 1, 2016, Molycorp may redeem the Senior Notes, in whole or in part, at a redemption price for the Senior Notes plus accrued and unpaid interest, initially at 105% of the principal amount thereof, but gradually declining to 100% of the principal amount thereof. In addition, at any time and from time to time prior to June 1, 2015, the Company may redeem up to 35% of the aggregate principal amount of the Senior Notes with the net cash proceeds of one or more permitted sales of Molycorp’s capital stock at a redemption price (expressed as a percentage of principal amount) of 110% plus accrued and unpaid interest. Upon the occurrence of a change of control, Molycorp will be required to offer to repurchase all of the Senior Notes. The Senior Notes are senior secured obligations of Molycorp and are guaranteed by certain of Molycorp’s domestic subsidiaries ("Guarantors"). The Senior Notes are secured by first-priority security interest on substantially all of the property and assets of the Company and the Guarantors, subject to some exceptions for certain "Excluded Assets," such as:
	•	Leasehold interests in real property
	•	Certain capital leases that constitute permitted liens
	•	Certain motor vehicles
	•	Assets owned by foreign subsidiaries or, subject to certain limitations, MMA
	•	Assets with a fair market value of less than $15.0 million as to which the board of directors determine in good faith (and certify to the collateral agent) that the costs of obtaining or perfecting such security interest are excessive in relation to the practical benefit to the holder of the Notes of the security afforded thereby (based on the value of such asset)
	•	Cash collateral for letters of credit or hedging obligations (up to 105% of the underlying obligations)
	•	Certain deposit accounts
	•	The equity interests of immaterial subsidiaries and, subject to certain limitations, MMA
	•	Voting stock of foreign subsidiaries in excess of 65.0% of the voting stock
	•	Other pledges of stock of a guarantor to the extent that Rule 3-16 of Regulation S-X under the Securities Act would require the filing of separate financial statements of such guarantor.
	A substantial portion of the net proceeds from the offering of the Senior Notes was used to fund the cash consideration the Company paid for Molycorp Canada, with the remainder used for general corporate purposes. The Company and the Guarantor filed an exchange offer registration statement with the SEC on November 23, 2012, which was declared effective on February 7, 2013.
	2011 Debt Issuance
	3.25% Convertible Notes
	On June 15, 2011, the Company issued $230.0 million aggregate principal amount (net proceeds of $223.1 million after deducting the initial purchasers’ discounts and commissions) of its 3.25% Convertible Notes due 2016 (the “3.25% Convertible Notes”) in an offering exempt from the registration requirements of the Securities Act. The Notes are senior unsecured obligations of the Company and bear interest at a rate of 3.25% per annum, payable semi-annually in arrears on June 15 and December 15 of each year, commencing on December 15, 2011. The 3.25% Convertible Notes are convertible at any time into shares of Molycorp’s common stock, cash, or a combination thereof, at Molycorp’s election. The initial conversion rate is 14.0056 shares of Molycorp common stock per $1,000 principal amount of the 3.25% Convertible Notes (equivalent to an initial conversion price of approximately $71.40 per share of Molycorp’s common stock), subject to customary adjustments. The 3.25% Convertible Notes mature on June 15, 2016, unless repurchased or converted in accordance with their terms. Molycorp does not have the right to redeem the 3.25% Convertible Notes prior to maturity.
	The Company separately accounts for the liability and equity components of convertible debt instruments, such as the 3.25% Convertible Notes, that may be settled entirely or partially in cash upon conversion in a manner that reflects the Company's economic interest cost. The additional discount on the liability component is amortized to interest cost over the term of the 3.25% Convertible Notes. The equity component of $36.2 million is included in additional paid-in capital in the consolidated balance sheet and is treated as original issue discount for purposes of accounting for the liability component. Transaction costs related to the issuance of the 3.25% Convertible Notes have been allocated to the liability and equity components in proportion to the allocation of proceeds to the components, and accounted for as debt issuance costs and equity issuance costs, respectively.
	Capital Leases
	At December 31, 2013, future minimum payments on the capital leases described below were $50.2 million, and are due as follows: $7.1 million in 2014, $7.1 million in 2015, $7.1 million in 2016, $6.0 million in 2017, $5.1 million in 2018 and $17.8 million thereafter. The aggregate amount of future minimum lease payments at December 31, 2013 includes total executory costs of $1.7 million and imputed interest of $26.9 million.
	2013 - Komatsu Equipment
	In 2013, the Company entered into seven capital lease agreements with Komatsu Equipment, each with a term of 48 months, for the use of certain mining equipment at its Molycorp Mountain Pass facility. The aggregate amount of future minimum lease payments for all capital lease agreements entered with Komatsu Equipment was $8.1 million at inception of the leases, which included a nominal amount of executory costs and imputed interest of approximately $0.7 million.
	2012 - Kern River
	On September 1, 2010, Molycorp and Kern River entered into a firm Transportation Service Agreement ("TSA") under which Kern River agreed to construct and operate facilities necessary to provide natural gas transportation services to the Mountain Pass facility. Under the terms of the TSA, Molycorp agreed to pay Kern River for the cost attributable to the design, permitting, and construction of the delivery facilities through a transportation service charge of approximately $0.4 million per month for ten years. This charge includes reimbursement to Kern River for construction of the delivery facilities and installation, as well as reimbursement and compensation for transportation services. The term of the TSA commenced on June 1, 2012, the date on which Kern River deemed the TSA facilities ready to provide service. The Company accounted for the TSA as a capital lease under the relevant accounting guidance. Aggregate future minimum lease payments were approximately $51.5 million at inception of this lease, which approximately included executory costs of $2.0 million and imputed interest of $33.2 million.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The Company’s net loss before income taxes and equity earnings for the year ended December 31, 2013 included an impairment charge of $27.2 million related to goodwill and other intangible assets, which is not deductible for tax purposes. The Company had net deferred income tax liabilities of $85.4 million at December 31, 2013 primarily related to the purchase accounting adjustment associated with the Molycorp Canada acquisition. The Company's management determined that a valuation allowance of $107.4 million was required at December 31, 2013. Furthermore, primarily due to the resolution with tax authorities, liabilities for uncertain tax positions decreased by a net amount of $5.2 million in fiscal 2013.
	For the years ended December 31, 2013, 2012 and 2011 our effective income tax rate was 16.4%, 10.3% and 19.5%, respectively. The 2013 effective income tax rate was impacted primarily by the valuation allowance required in both the U.S. and Canada, and the difference in tax rates between the U.S. and foreign jurisdictions.
	The Company had undistributed earnings of certain foreign subsidiaries at December 31, 2013 for which deferred taxes of $14.8 million have been provided. Also, it had undistributed earnings of certain foreign subsidiaries at December 31, 2013, for which deferred taxes have not been provided. Such earnings are considered indefinitely invested in the foreign subsidiaries. If such earnings were repatriated, additional tax expense may result, although the calculation of such additional taxes is not practicable.
	The net tax effect of the elimination in consolidation of intercompany balances and transactions resulted in a deferred charge and income tax payable of $1.0 million at December 31, 2013.
	Income tax expense consisted of the following for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	Current
	Federal	$	(2,581	)	$	(22,418	)	$	18,721
	Foreign	(1,018		)	8,994			—
	State	792			(4,197		)	6,952
	Total current	(2,807		)	(17,621		)	25,673
	Deferred
	Federal	(43,479		)	(20,786		)	3,687
	Foreign	(16,517		)	(11,777		)	—
	State	(8,140		)	(3,891		)	(784		)
	Total deferred	(68,136		)	(36,454		)	2,903
	Total tax provision	$	(70,943	)	$	(54,075	)	$	28,576
	The components of earnings before income taxes, by tax jurisdiction, were as follows for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	United States	$	(286,818	)	$	(161,129	)	$	141,801
	Foreign	(145,458		)	(363,062		)	5,109
	Total	$	(432,276	)	$	(524,191	)	$	146,910
	A reconciliation of the statutory federal income tax rate of 35% to the Company's effective income tax rate is as follows for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	Federal tax computed at the statutory rate	$	(151,297	)	$	(184,075	)	$	51,419
	State taxes, net of federal benefit	(10,329		)	(5,970		)	5,255
	Change in valuation allowance	85,881			19,515			(22,730		)
	Impairment of goodwill and other long-lived assets	7,458			103,563			—
	Acquisition costs	—			4,945			—
	Changes related to uncertain tax positions	(5,153		)	(14,176		)	—
	Federal and State tax credits	2,946			(6,817		)	(2,627		)
	Domestic production activities deduction	—			2,493			(2,493		)
	Foreign income tax rate differential	24,315			18,682			(1,735		)
	Foreign translation adjustments	(7,744		)	—			—
	Change in applicable law	(5,884		)	—			—
	Other items, net	(11,136		)	7,765			1,487
	Income tax expense	$	(70,943	)	$	(54,075	)	$	28,576
	The tax effect of temporary differences and net operating losses, which give rise to deferred tax assets and liabilities, consisted of the following at December 31, 2013 and 2012:
		At December 31,
		2013			2012
		(In thousands)
	Deferred tax assets:
	Current:
	Inventory	$	2,570		$	11,951
	Other	2,605			2,468
	Total current	5,175			14,419
	Non-current:
	Asset retirement obligation	—			165
	Mineral resources	16,886			16,780
	Property, plant and equipment and intangible assets	21,044			13,435
	Stock compensation	1,964			1,724
	Net operating losses	144,366			56,156
	Research and energy tax credits	6,233			10,473
	Alternative Minimum Tax Credit	2,216			1,611
	Unrealized foreign exchange	5,664			—
	Investments	3,120			—
Other	4,107			823
Total non-current	205,600			101,167
Deferred tax liabilities:
Current
Inventory	1,312			3,395
Other	1,423			541
Total current	2,735			3,936
Non-current:
Asset retirement obligation	1,190			—
Foreign subsidiary earnings and withholding taxes	14,804			32,637
Property, plant and equipment and intangible assets	91,585			137,010
Section 174 costs	33,942			24,814
Convertible debt (Notes)	44,275			40,478
Other	302			6,966
Total non-current	186,098			241,905
Net deferred taxes, before valuation allowance	21,942			(130,255		)
Valuation allowance	(107,358		)	(20,631		)
Total deferred tax	$	(85,416	)	$	(150,886	)
At December 31, 2013, the Company had tax credit carryforwards of $8.4 million available to offset future income taxes. Of this amount, $2.2 million are available to carry forward indefinitely, while $6.0 million of the remaining $6.2 million will expire between 2028 and 2032, if not utilized.
The U.S. federal tax loss carryforward was approximately $290.7 million at December 31, 2013, of which $28.6 million will expire in 2023 and the remainder in 2032 and 2033. The U.S. state tax loss carryforward of approximately $270.1 million at December 31, 2013 will expire primarily between 2031 and 2033, if not utilized. The federal loss carryforward could be subject to examination by the tax authorities until three years after the carryforward is utilized while the state carryforward could be subject to examination until four years after the carryforward is utilized. Additionally, the Company had approximately $165.1 million of tax loss carryforwards for controlled foreign corporations at December 31, 2013 that will expire between 2021 and 2033, if not utilized.
It is possible that the common stock offering completed in October 2013, in combination with past and future transactions involving the Company’s common stock, may cause an ownership change to occur that would limit the Company’s ability to use U.S. net operating loss carryforwards and other tax attributes. However, if an ownership change were to occur, the Company does not anticipate a significant impact on its income tax benefit.
The Company conducts business in a country that grants “holidays” from income taxes. This “holiday” expires in 2019. The current operations in the tax “holiday” country have not resulted in material aggregate income tax benefits and related earnings per share benefits as of December 31, 2013.
Each quarter the Company evaluates the liability for uncertain tax positions. Due to a lapse of the applicable statute of limitations and due to the resolution with tax authorities, the Company's unrecognized tax benefits decreased by $5.2 million during 2013. The Company believes that it is reasonably possible that the total amount of its net unrecognized income tax benefits will not change materially in the 12 months following December 31, 2013 and, as a result, would not affect the Company's effective income tax rate. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows:
	Years Ended December 31,
	2013			2012			2011
	(In thousands)
Balance, beginning of year	$	6,219		$	519		$	—
Tax position related to current year:
Additions	—			4,737			519
Tax positions related to prior years:
Additions	—			16,109			—
Settlements	(4,737		)	(13,740		)	—
Statute of limitations closures	(416		)	(1,406		)	—
Balance, end of year	$	1,066		$	6,219		$	519
The Company operates and accordingly files income tax returns in the U.S. federal jurisdiction, various U.S. state jurisdictions, as well as foreign jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state, and non-U.S. income tax examinations by tax authorities for years prior to 2010.
The Company does recognize accrued interest and penalties related to uncertain tax positions in income tax expense for the years ended December 31, 2013, 2012 and 2011, as applicable.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity	'
	Stockholders’ Equity
	2013 Public Equity Issuance (October)
	On October 21, 2013, the Company issued 51,750,000 shares of its common stock, which included the issuance of 6,750,000 shares as a result of the underwriters’ exercise in full of their option to purchase additional shares in the same offering, at a price per share of $5.00. The underwriters received a 5.00% fee in the form of an underwriter's discount. Certain officers, directors and other related parties of the Company participated in this offering by purchasing 14,034,000 of the total shares issued; no underwriting fees were charged to the Company for the purchases of the shares by the insiders. The issuance of these shares resulted in net proceeds to the Company, after deducting the underwriting discounts, commissions and issuance costs payable by the Company, of approximately $247.5 million.
	2013 Public Equity Issuance (January)
	On January 30, 2013, the Company issued 37,500,000 shares of its common stock at a price per share of $6.00 (the “2013 Primary Shares”). The underwriters of this public offering purchased an additional 5,625,000 shares of the 2013 Primary Shares at a price per share of $6.00 on February 5, 2013, and received a 6.00% fee in the form of an underwriter's discount on the total shares issued. Certain officers, directors and other related parties of the Company participated in offering of the 2013 Primary Shares by purchasing 15,016,666 of the total 2013 Primary Shares issued; no underwriting fees were charged to the Company for the purchases of the 2013 Primary Shares by the insiders. After deducting the underwriting discounts, commissions and issuance costs payable by the Company, total net proceeds from the issuance of the 2013 Primary Shares were $248.1 million.
	Concurrently with the 2013 Primary Shares, and in order to facilitate the offering of the 5.50% Convertible Notes further discussed in Note 14, the Company entered into a share lending agreement with Morgan Stanley Capital Services LLC (“MSCS”), an affiliate of Morgan Stanley & Co. LLC, under which it agreed to loan to MSCS up to 7,666,666 shares of common stock (the “2013 Borrowed Shares”), of which 6,666,666 were issued at a price per share of $6.00 in a registered public offering. MSCS did not exercise its option to borrow the remaining additional shares of common stock under this share lending agreement. The Company received no proceeds from the 2013 Borrowed Shares, but only a nominal lending fee from MSCS for the use of these loaned shares. The 2013 Borrowed Shares are issued and outstanding for corporate law purposes. However, based on certain contractual undertakings of MSCS in the share lending agreement that have the effect of substantially eliminating the economic dilution that otherwise would result from the issuance of the 2013 Borrowed Shares, these loaned shares will not be considered outstanding for the purpose of computing and reporting Molycorp's earnings per share.
	2012 Private Equity Issuance (Acquisition of Exploration Rights)
	During the fourth quarter of 2012, the Company completed an acquisition of exploration rights for total consideration of $16.2 million, which was paid for by the issuance of 788,410 shares of the Company's common stock at $10.147 per share and a cash payment of $8.2 million. As described in Note 8, the Company recorded an impairment charge of $16.2 million relating to these exploration rights in the fourth quarter of 2013.
	2012 Public Equity Issuance
	In August 2012, concurrently with the issuance of the 6.00% Convertible Notes further discussed in Note 14, the Company issued a total of 13,800,000 shares of its common stock at a price to the public of $10.00 per share (the “Primary Shares”) in a separate underwritten public offering. The underwriters received a 6.00% fee in the form of an underwriter's discount for the Primary Shares plus a $1.5 million flat fee to the representative of the underwriters of the Primary Shares. Certain officers, directors and other related parties of the Company participated in offering of the Primary Shares by purchasing 7,090,000 of the total Primary Shares issued, but no underwriting fees were charged to the Company for the purchase by the insiders. After deducting the underwriting discounts, commissions, the flat fee and issuance costs payable by the Company, total net proceeds from the issuance of the Primary Shares were $132.1 million.
	At the same time of the issuance of the 6.00% Convertible Notes and the Primary Shares the Company entered into a share lending agreement with MSCS and, between August 22, 2012 and August 23, 2012, the Company issued 13,800,000 shares of common stock to MSCS (the “Borrowed Shares”). The Company received no proceeds from the issuance of the Borrowed Shares, but only a nominal lending fee from MSCS for the use of these loaned shares. For corporate law purposes, the Borrowed Shares are issued and outstanding. However, based on certain contractual undertakings of MSCS in the share lending agreement that have the effect of substantially eliminating the economic dilution that otherwise would result from the issuance of the Borrowed Shares, these loaned shares will not be considered outstanding for the purpose of computing and reporting Molycorp's earnings per share.
	2012 Issuance of Shares for Interest in Molycorp Canada
	In connection with of the acquisition of Molycorp Canada on June 11, 2012, the Company and MCP Exchangeco Inc. issued an aggregate of 13,545,426 shares of common stock and 507,203 Exchangeable Shares, respectively, in consideration for that portion of the purchase price the Company paid to Molycorp Canada’s former shareholders who elected to receive shares of the Company and MCP Exchangeco Inc. common stock in addition to or in lieu of cash on the acquisition date. The Exchangeable Shares were issued without par value. The $284.1 million aggregate fair value of the Company and MCP Exchangeco Inc. common stock shares was based on the closing price of the Company’s common stock on June 11, 2012. As of December 31, 2012, 340,196 shares of the Exchangeable Shares had been converted into shares of Molycorp common stock.
	During 2013, additional 18,616 Exchangeable Shares were converted into shares of Molycorp common stock for a total of 358,812 shares converted through December 31, 2013. The conversion of the Exchangeable Shares increases the outstanding number of shares of the Company's common stock.
	In August 2012, as a result of the conversion of the Debentures assumed from the Molycorp Canada acquisition, as further discussed in Note 14, a portion of the Debentures tendered was converted into 99,723 shares of Molycorp common stock. Additional Debentures were converted into 2,471 shares of Molycorp common stock during 2013, for a total of 102,194 shares converted through December 31, 2013.
	2012 Private Equity Issuance (Molymet)
	On March 8, 2012, Molymet, the world’s largest processor of molybdenum and rhenium, headquartered in Santiago, Chile, purchased 12,500,000 shares of the Company’s common stock for $390.1 million, net of stock issuance costs of $0.1 million, at a purchase price of $31.218 per share, which price was determined based on the average daily volume weighted average price of the Company’s common stock on The New York Stock Exchange for the 20 consecutive trading days immediately preceding the date of the agreement, plus a 10% premium. Pursuant to this investment, Molymet acquired the right to nominate a member of the Company’s Board of Directors for so long as Molymet owns a certain percentage of the Company’s common stock.
	2011 Public Equity Issuance (Convertible Preferred Stock)
	On February 16, 2011, Molycorp completed a public offering of its 5.50% Series A Mandatory Convertible Preferred Stock (“Convertible Preferred Stock”), $0.001 par value per share. In connection with this offering, the Company issued 1,800,000 shares of Convertible Preferred Stock for $100.00 per share. In addition, Molycorp granted the underwriters an option to purchase up to 270,000 additional shares of Convertible Preferred Stock to cover over-allotments. The underwriters exercised their option to purchase the additional shares of Convertible Preferred Stock on March 16, 2011. Each share of the Convertible Preferred Stock will automatically convert on March 1, 2014 into between 1.6667 and 2.0000 shares of Molycorp’s common stock, subject to anti-dilution adjustments. At any time prior to March 1, 2014, holders may elect to convert each share of the Convertible Preferred Stock into shares of common stock at the minimum conversion rate of 1.6667 shares of common stock per share of Convertible Preferred Stock, subject to anti-dilution adjustments. Dividends on the Convertible Preferred Stock are payable on a cumulative basis when, as and if declared by the Board or an authorized committee of such Board, at an annual rate of 5.50% on the liquidation preference of $100.00 per share. The Company may pay declared dividends in cash, common stock or any combination of cash and common stock, subject to certain limitations, on March 1, June 1, September 1 and December 1 of each year, starting on June 1, 2011 and to, and including, March 1, 2014. The Convertible Preferred Stock is not redeemable. Molycorp received net proceeds from the Convertible Preferred Stock issuance totaling $199.6 million after underwriter discounts and commissions and other offering expenses paid by the Company.
	In 2013 and 2012, the Company declared a quarterly cash dividend of $1.375 per share on the Convertible Preferred Stock and paid a total of $11.4 million cash dividends in each year. In 2011, the Company declared and paid a $9.0 million cash dividend.

Earnings_per_Share

Earnings per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings per Share	'
	Earnings per Share
		Years Ended December 31,
		2013			2012			2011
		(In thousands, except share and per share amounts)
	Net (loss) income attributable to Molycorp stockholders	$	(374,383	)	$	(481,169	)	$	117,526
	Dividends on Convertible Preferred Stock	(11,385		)	(11,385		)	(9,962		)
	(Loss) income attributable to common stockholders	(385,768		)	(492,554		)	107,564
	Continuing operations	$	(379,341	)	$	(490,817	)	$	107,564
	Discontinued operations	(6,427		)	(1,737		)	—
		$	(385,768	)	$	(492,554	)	$	107,564
	Weighted average common shares outstanding—basic	174,528,717			107,064,892			83,454,221
	Basic (loss) earnings per share from:
	Continuing operations	$	(2.17	)	$	(4.58	)	$	1.29
	Discontinued operations	(0.04		)	(0.02		)	—
		$	(2.21	)	$	(4.60	)	$	1.29
	(Loss) income attributable to common stockholders	$	(385,768	)	$	(492,554	)	$	107,564
	Effect of dilutive 3.25% Convertible Notes	—			—			413
	Adjusted (loss) income attributable to common stockholders	(385,768		)	(492,554		)	107,977
	Continuing operations	$	(379,341	)	$	(490,817	)	$	107,977
	Discontinued operations	(6,427		)	(1,737		)	—
		$	(385,768	)	$	(492,554	)	$	107,977
	Weighted average common shares outstanding—diluted	174,528,717			107,064,892			85,220,017
	Diluted (loss) earnings per share from:
	Continuing operations	$	(2.17	)	$	(4.58	)	$	1.27
	Discontinued operations	(0.04		)	(0.02		)	—
		$	(2.21	)	$	(4.60	)	$	1.27
	Diluted earnings per share reflect the dilutive impact of potential common stock and unvested restricted shares of common stock in the weighted average number of common shares outstanding during the period, if dilutive. For this purpose, the “treasury stock method” and “if-converted method,” as applicable, are used.
	Under the treasury stock method, assumed proceeds upon the exercise of stock options are considered to be used to purchase common stock at the average market price of the shares during the period. Also under the treasury stock method, fixed awards and nonvested shares, such as restricted stock units, are deemed options for purposes of computing diluted earnings per share. For the years ended December 31, 2013, 2012 and 2011, all potential common stock under the treasury stock method were antidilutive in nature; consequently, the Company did not have any adjustments between earnings per share and diluted earnings per share related to stock options and restricted stock units.
	In applying the if-converted method, conversion is not assumed for purposes of computing diluted earnings per share if the effect would be antidilutive. Convertible preferred stock (such as the Convertible Preferred Stock) is antidilutive whenever the amount of the dividend declared in or accumulated for the current period per common share obtainable on assumed conversion, including the deemed dividend in the period from a beneficial conversion feature, exceeds basic earnings per share. The Convertible Preferred Stock was antidilutive for the years ended December 31, 2013, 2012 and 2011.
	Also, under the if-converted method, convertible debt (such as the 3.25%, the 6.00% and the 5.50% Convertible Notes) is antidilutive whenever the related interest per common share obtainable on assumed conversion, including any deemed interest from a beneficial conversion feature and nondiscretionary adjustments, net of tax, exceeds basic earnings per share. For the years ended December 31, 2013 and 2012, the 3.25%, the 6.00% and the 5.50% Convertible Notes were antidilutive. The 3.25% Convertible Notes were dilutive for the year ended December 31, 2011 and, as a result, the shares of common stock obtainable on the assumed conversion of the 3.25% Convertible Notes, the interest expense and the amortization of discount, net of income tax, were included in the computation of diluted earnings per share for 2011.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	Stock-Based Compensation
	Molycorp has stock-based compensation plans for executives, eligible employees and non-employee directors. Stock-based awards issued under these plans include stock options to purchase shares of the Company’s common stock, restricted stock awards (“RSAs”), restricted stock units (“RSUs”) and performance-based restricted stock units ("PBRSUs"). The remaining number of shares authorized for awards of equity share options or other equity instruments was 2,055,435 at December 31, 2013. The Company recognized total annual stock-based compensation expenses and related income tax benefit as follows:
		2013		2012		2011
		(In millions)
	Stock-based compensation expense	$5.40		$3.40		$4.70
	Income tax benefit	$—		$0.90		$0.80
	Stock-based compensation expense for the years ended December 31, 2013 and 2012 includes forfeiture benefits of $1.5 million and $1.6 million, respectively.
	RSAs, RSUs and PBRSUs
	RSUs and RSAs vest on the third anniversary of the grant date. The grant-date fair value of RSUs and RSAs is determined using the Company’s common stock price on the date of grant and is recognized as stock-based compensation expense on a straight-line basis over the three-year vesting period for the awards that are expected to vest. The PBRSUs vest with respect to between 0% and 150% of the PBRSUs granted to an individual on the basis of the achievement of certain management objectives measured by specified levels of total shareholder return relative to a defined index group over the performance period from January 1, 2012 through December 31, 2014, or upon the occurrence of certain change of control or termination events. The grant-date fair value of PBRSUs is determined using a lattice approach that incorporates a Monte Carlo simulation model. The compensation cost associated with the PBRSUs is recognized on a straight-line basis over the performance period for the awards that are expected to vest, even if the market conditions are never satisfied.
	Certain RSUs granted to the non-employee directors in 2013 relate to the grantees' election to convert a portion of their quarterly cash retainer into RSUs. These RSUs are fully vested because they relate to services already rendered by the non-employee directors. The same non-employee directors who elected to convert their cash retainer into RSUs, received additional RSUs as matching contributions by the Company equal to 25% of the converted units. The matching RSUs vest on the third anniversary of the grant date with the related compensation cost recognized on a straight-line basis over the vesting period.
	Certain other RSUs issued in 2013 relate to the election by certain executive officers and other employees of the Company to convert a portion of their 2012 annual cash bonuses into RSUs. These RSUs are fully vested because they relate to services already rendered by the grantees. The same executive officers and other employees who elected to convert a portion of their 2012 annual cash bonuses into RSUs received additional RSUs as matching contribution by the Company equal to 25% of the converted RSUs. The matching RSUs vest on the third anniversary of the grant date with the related compensation cost recognized on a straight-line basis over the vesting period.
	The following tables summarize the activity related to restricted stock-based awards for the year ended December 31, 2013:
	PBRSUs	Number of			Weighted Average
		Shares			Grant-Date
					Price
	Unvested at January 1, 2013	29,302			$30.33
	Granted	897,515			$6.84
	Forfeited	(69,546	)		$11.00
	Vested	(159,474	)		6.64
	Unvested at December 31, 2013	697,797			$7.45
	RSUs	Number of			Weighted Average
		Shares			Grant-Date
					Price
	Unvested at January 1, 2013	181,602			$32.15
	Granted	1,005,757			$7.02
	Forfeited	(85,119	)		$27.15
	Vested*	(25,855	)		$6.89
	Unvested at December 31, 2013	1,076,385			$9.81
	*	Includes: a) deferral and conversion of a portion of fees payable to certain non-employee directors of the Company; b) deferral and conversion of a portion of the 2012 annual cash bonuses paid to certain executive officers and other employees of the Company; and c) RSUs with an accelerated vesting period that were granted to some employees of Molycorp Canada on the acquisition date.
	RSAs	Number of			Weighted Average
		Shares			Grant-Date
					Price
	Unvested at January 1, 2013	39,974			$40.09
	Granted	—			—
	Forfeited	(8,148	)		$39.77
	Vested	(25,500	)		$36.51
	Unvested at December 31, 2013	6,326			$55.05
	Additional annual information for restricted stock-based awards is included in the following tables:
	PBRSUs	2013		2012		2011
		(In millions)
	Weighted average grant-date fair value of shares granted	$6.10		$1.40		n/a
	Total fair value of shares vested	$1.10		n/a		n/a
	RSUs	2013		2012		2011
	Weighted average grant-date fair value of shares granted	$7.10		$5.50		$4.50
	Total intrinsic value of share units converted	$0.20		$0.40		$0.10
	Total fair value of shares vested	$0.20		$0.80		$0.10
	RSAs	2013		2012		2011
	Weighted average grant-date fair value of shares granted	n/a		n/a		$0.60
	Total fair value of shares vested	$0.90		n/a		n/a
	At December 31, 2013, there was $9.7 million of aggregate unrecognized compensation cost related to the unvested shares of RSAs, RSUs and PBRSUs. This cost is expected to be recognized over a weighted-average period of approximately 2.15 years.
	Stock Options
	The Company has not granted any stock options since January 2011. Previously issued stock options vest in equal installments annually over a 3-year period and have a 10-year contractual term from the grant date. The fair value of each stock option award was estimated at the grant date using the Black-Scholes option pricing model and the Company’s common stock price on the date of grant. The significant assumptions used to estimate the fair value of the stock options granted in 2011 were as follows:
	Risk-free interest rate	2.21%
	Expected term (in years)	6
	Volatility	60.10%
	Expected dividend yield	0
	The risk-free interest rate used was the yield of a zero-coupon U.S. Treasury bond with a term equal to the expected term of the options. Because it did not have sufficient historical exercise and post-vesting data, the Company calculated the expected term of options granted in 2011 by using an average of the midpoint between when options become exercisable and when they expire. The volatility assumption were computed based on a peer group analysis by reference to SAB Topic 14 given that the Company had been publicly traded for a few months at the time of granting the 2011 stock options.
	Stock options outstanding and exercisable at December 31, 2013 had a weighted average remaining contractual term of 3.04 years and no intrinsic value. The following table summarizes the activity related to stock options in 2013:
	Stock Options	Number of			Weighted Average
		Shares			Exercise Price
	Outstanding at January 1, 2013	35,624			$48.87
	Granted	—			—
	Exercised	—			—
Forfeited and expired	(9,008	)		48.87
Outstanding at December 31, 2013	26,616			$48.87
Options exercisable at December 31, 2013	17,744			$48.87
Additional annual information for stock options is included in the following table:
	2013		2012		2011
	(In millions)
Weighted average grant-date fair value of options granted	n/a		n/a		$1.50
Total intrinsic value of options exercised	n/a		n/a		n/a
Total fair value of options vested	$0.50		$0.30		n/a
At December 31, 2013, there was a nominal unrecognized compensation cost related to stock options.
Employee Stock Purchase Plan
In December 2012, the Company introduced an Employee Stock Purchase Plan ("ESPP") to provide eligible employees with an opportunity to acquire a proprietary interest in the Company through the purchase of its common stock at a discount over the stock fair market value. The maximum aggregate number of shares of common stock that may be issued under the ESPP is 300,000 shares and consists of authorized but unissued or treasury shares, or any combination thereof. The ESPP is implemented by sequential offering periods, the commencement and duration of which are determined by the Board of Directors ("Board") of Molycorp. During 2013, the Company recognized stock-based compensation expense of $0.1 million related to the ESPP, which was measured at the grant dates based on the number of shares that could be purchased using the estimated total withholdings and the grant-date fair value of one share (determined as the sum of the discount offered by the Company and the share-option fair value of the stock price reduced by the discount at the beginning of each offering period). At December 31, 2013, there were 28,436 committed-to-be-released shares of the Company's common stock under the ESPP.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	(a)	Future Operating Lease Commitments
	The Company leased certain office space, trailers and equipment pursuant to lease agreements that have been determined to be operating lease. Remaining annual minimum payments under these leases at December 31, 2013 were as follows:
	(In thousands)	Total		Less Than		1 - 3 Years		4 - 5 Years		More Than
				1 Year						5 Years
	Operating lease obligations	$	6,283	$	2,583	$	2,263	$	442	$	995
	Rent expense under these leases totaled $4.0 million, $4.1 million and $0.7 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	(b)	Purchase Commitments
	The Company entered into contractual commitments for the purchase of materials and services from various vendors, primarily in connection with the Molycorp Mountain Pass facility modernization and expansion efforts. Future payments for all purchase commitments at December 31, 2013 were as follows:
	(In thousands)	Total		Less Than		1 - 3 Years		4 - 5 Years		More Than
				1 Year						5 Years
	Purchase obligations and other commitment	$	238,945	$	216,249	$	12,813	$	6,239	$	3,644
	(c)	Labor Contract
	Certain Molycorp Mountain Pass facility employees are covered by a collective bargaining agreement with the United Steelworkers of America that expires on March 15, 2015. At December 31, 2013, 237 employees, or approximately 61% of the Company’s workforce at the Molycorp Mountain Pass facility, were covered by this collective bargaining agreement.
	At December 31, 2013, 171 employees, or approximately 30% of the workforce at the Company’s Molycorp Silmet facility, were unionized employees. The contract with the labor union in Estonia is automatically renewed each year unless either party desires to make an amendment. The contract that was last amended in February 2012.
	(d)	Reclamation Surety Bonds
	At December 31, 2013, Molycorp had placed $28.8 million of surety bonds with California state and regional agencies to secure its Mountain Pass facility closure and reclamation obligations.
	(e)	Purported Class Action, Derivative Lawsuits
	In February 2012, a purported class action lawsuit was filed in the U.S. District Court for the District of Colorado against the Company and certain of its current and former executive officers alleging violations of the federal securities laws. The Consolidated Class Action Complaint filed on July 31, 2012 also names most of the Company's Board members and some of our stockholders as defendants, along with other persons and entities. That Complaint alleges 18 claims for relief arising out of alleged: (1) securities fraud in violation of the Securities Exchange Act of 1934, or the Exchange Act, during the proposed class period from February 11, 2011 through November 10, 2011; and (2) materially untrue or misleading statements in registration statements and prospectuses for our public offering of preferred stock in February 2011 and of common stock in June 2011, in violation of the Securities Act. The Company's motion to dismiss that Complaint was filed in October 2012 and is pending. The Company believes that this lawsuit is without merit, and it intends to vigorously defend itself against these claims.
	A consolidated shareholder derivative lawsuit filed purportedly on the Company's behalf against the Company (as a nominal defendant) and certain of its current and former directors, executive officers and shareholders is pending in the Delaware Court of Chancery. In August 2012, a consolidated amended shareholder derivative complaint was filed, asserting causes of action for alleged: (1) breach of fiduciary duty, including the duties of loyalty and due care; (2) breach of fiduciary duty not to trade on or misuse material non-public information; (3) unjust enrichment; and (4) aiding and abetting a breach of fiduciary duty. On the Company's behalf, the plaintiffs in the consolidated derivative action seek, among other things, monetary damages, restitution, and an accounting. The defendants filed motions to dismiss and motions to stay that action in October 2012. Pursuant to an order dated May 15, 2013, the Delaware Court of Chancery stayed the derivative lawsuit pending final disposition of the purported class action lawsuit. On October 9, 2013, certain plaintiffs, on the Company's behalf, filed a Motion to Lift the Stay and for Leave to File an Amended Complaint. All briefs in respect of this motion have been filed, and a hearing on the motion was held on February 7, 2014. Two additional shareholder derivative lawsuits that were filed in the U.S. District Court in Colorado have been dismissed, but the plaintiffs in those cases pursued an appeal of that ruling in the U.S. Court of Appeals for the Tenth Circuit. On August 20, 2013, the Tenth Circuit remanded these cases back to the Colorado District Court. Both the Company and the plaintiffs have filed their respective briefs in the remanded proceeding and the decision of the Colorado District Court is pending. Subsequently, a different shareholder filed purportedly on the Company's behalf a new shareholder derivative lawsuit in the U.S. District Court in Colorado on November 20, 2013. On December 11, 2013, the Colorado District Court sua sponte consolidated the new derivative lawsuit with the two remanded lawsuits, and permitted the plaintiff in the new derivative lawsuit to file a brief in the remanded proceeding. On December 27, 2013, the plaintiff in the new derivative lawsuit filed its brief in the remanded proceeding, and filed a motion to vacate the consolidation order. The decision of the Colorado District Court on each of the remanded proceeding and the motion to vacate the consolidation order is pending. Pursuant to an order the Colorado District Court entered on January 7, 2014 the defendants need not respond to the new derivative lawsuit until the Colorado District Court decides the defendants’ motion to dismiss or stay the remanded proceeding.
	In August 2013, two purported class action lawsuits were filed in the U.S. District Court for the Southern District of New York against the Company and certain of its current and former executive officers, alleging violations of the federal securities laws. The purported class action lawsuits allege claims for relief arising out of alleged securities fraud in violation of the Exchange Act during the proposed class period from August 2, 2012 through August 7, 2013. Pursuant to stipulations and orders of the court dated September 25, 2013 and September 27, 2013, among other things, the deadlines for the Company and its current and former executive officers to respond to the lawsuits have been stayed pending appointment of a lead plaintiff under the Private Securities Litigation Reform Act. The Company believes that the lawsuits are without merit, and it intends to vigorously defend itself against these claims.
	Due to the inherent uncertainties of litigation and regulatory proceedings, including the current purported class action lawsuit and derivative lawsuits, the Company cannot determine with certainty the ultimate outcome of any such litigation or proceedings. If the final resolution of any such litigation or proceedings is unfavorable, our financial condition, operating results and cash flows could be materially affected.

Concentrations

Concentrations	12 Months Ended
	Dec. 31, 2013
Risks and Uncertainties [Abstract]	'
Concentrations	'
	Concentrations
	Resources Segment
	There were no significant sales by customer or by product during 2013 or 2012 at the Resources segment relative to consolidated revenues. In 2011, significant sales by product at the Resources segment, relative to consolidated revenues, included lanthanum products 23%, cerium products 11% and neodymium/praseodymium products 26%. Additionally, sales to Hitachi Metals Ltd. totaled $92.2 million, or 23% of consolidated revenues.
	Chemicals and Oxides Segment
	Sales of cerium products within the Chemicals and Oxides segment accounted for approximately 9.0% and 15% of consolidated sales in 2013 and 2012, respectively. There were no significant sales by customer in this segment in 2013, 2012 and 2011; however, two customers accounted for approximately 26% of the consolidated accounts receivable balance at December 31, 2013.
	Magnetic Materials and Alloys Segment
	Sales of Neo Powders™ within the Magnetic Materials and Alloys segment were approximately 41% and 25% of consolidated revenues in 2013 and 2012, respectively. Neo Powders™ were introduced into Molycorp's product mix with the Molycorp Canada acquisition.
	In 2013 and for the period from June 12, 2012 to December 31, 2012, sales of Neo Powders™ to Daido Electronics, a subsidiary of one of IMJ’s shareholders, totaled $56.5 million and $32.9 million, respectively. At December 31, 2013, the Company had accounts receivable from Daido Electronics of $7.5 million.
	In 2011, sales of NdFeB alloys in this segment were approximately 11% of consolidated revenues. Additionally, sales to Santoku Corporation were $48.8 million, or approximately 12% of the consolidated revenues.
	Rare Metals Segment
	There were no significant sales by product and by customer at the Rare Metals segment in 2013, 2012 and 2011.

RelatedParty_Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related-Party Transactions	'
	Related-Party Transactions
	The Company supplies Neo Powders™ to Toda Magnequench Magnetic Materials Co. Ltd. (“TMT”), an equity method investee, to produce rare earth magnetic compounds. The Company then purchases these compounds back from TMT in its normal course of business. Additionally, Keli, another equity method investee, processes rare earth oxides into metals for inclusion in the Neo Powders™.
	In 2013 and for the period from June 12, 2012 to December 31, 2012, the Company sold $4.5 million and $1.6 million, respectively, of Neo Powders™ to TMT and purchased $2.1 million and $2.8 million, respectively, worth of compounds from TMT.
	The Company purchased metals and received services from Keli for a total of $61.3 million and $32.6 million in 2013 and for the period from June 12, 2012 to December 31, 2012, respectively.
	Ingal Stade, an equity method investee, sells gallium to the Company's facilities in Canada and the U.S. In 2013 and for the period from June 12, 2012 to December 31, 2012, the Company purchased gallium metal from Ingal Stade of approximately $4.9 million and $3.3 million, respectively.
	The Company provides recycling services to Plansee, Holding AG ("Plansee"), a privately held Austrian company in which one of the Company's directors and members of his family own a related interest. The director joined the Company's Board in August 2013. The Company received $0.3 million from Plansee for recycling services provided during the period from August 1, 2013 to December 31, 2013.

Net_Change_in_Operating_Assets

Net Change in Operating Assets and Liabilities	12 Months Ended
	Dec. 31, 2013
Net Change in Operating Assets and Liabilities	'
Net Change in Operating Assets and Liabilities	'
	Net Change in Operating Assets and Liabilities
	Net change in operating assets and liabilities, net of the effects of acquisitions and dispositions, consisted of the following:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	Decrease (increase) in operating assets:
	Accounts receivable	$	(8,986	)	$	124,983		$	(52,805	)
	Inventory	15,649			(46,126		)	(64,543		)
	Prepaid expenses and other assets	(5,728		)	33,520			(6,363		)
	Increase (decrease) in operating liabilities:
	Accounts payable	(24,177		)	(34,972		)	16,233
	Income tax payable	18,966			(40,263		)	(17,832		)
	Interest payable	(39,120		)	(40,792		)	—
	Asset retirement obligation	(7,642		)	(1,467		)	(1,030		)
	Accrued expenses	(13,681		)	(54,763		)	6,151
		$	(64,719	)	$	(59,880	)	$	(120,189	)

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2013
Supplemental Cash Flow Elements [Abstract]	'
Supplemental Cash Flow Information	'
	Supplemental Cash Flow Information
		Years Ended December 31,
		2013		2012	2011
		(In thousands of dollars)
	Net cash paid for:
	Income taxes	(13,429	)	178	43,505
	Interest, net of capitalized interest	32,833		8,942	273
	Non-cash financing activities and investing activities:
	Change in accrued capital expenditures	58,673		52,189	112,606
	Conversion of debt securities to equity securities	18		4,527	—
	Acquisition of exploration rights	—		8,000	—
	Debt assumed from business acquisitions	—		40,691	3,184
	Issuance of common stock for business acquisitions	—		284,100	72,700
	Fixed assets additions under capital lease	7,370		15,658	—

Derivative_Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Derivative Instruments	'
	Derivative Instruments
	Put Option
	As a result of the Molycorp Canada acquisition, the Company assumed a liability associated with the put option issued to holders of the noncontrolling interest of Buss & Buss, a business acquired by Molycorp Canada's predecessor company. The Buss & Buss put option relates to a share purchase agreement (“SPA”) between NMT Holding GmbH, a German subsidiary of the Company, and the shareholders of Buss & Buss entered into May 27, 2010 by Molycorp Canada's predecessor company. The SPA includes a call and a put option on shares of the remaining shareholder and his legal successors. If the call option is exercised by the Company, a premium is added to the consideration to purchase the underlying shares in Buss & Buss. If the put option is exercised by the remaining shareholder of Buss & Buss or his legal successors, a discount will reduce the cost basis of the securities sold to the Company. The Company accounts for the put option at fair value with changes in fair value recognized currently in earnings. The put option had a fair value of $6.1 million and $7.8 million at December 31, 2013 and 2012, respectively, while the related is reflected "Derivative liability" in the consolidated balance sheet. The change in fair value of the put option resulted in an unrealized gain of $1.7 million and $1.2 million for the year ended December 31, 2013 and 2012, respectively, which is reflected in "Interest expense" in the consolidated statement of operations and comprehensive income. The technique used by the Company to fair value this derivative is the income approach based on a discounted cash flow model. In addition to the risk free interest rate, which is a Level 1 input within the fair value hierarchy, the following significant unobservable Level 3 inputs were used to fair value the put option as of December 31, 2013:
				Effect of 1% increase (a)			Effect of 1% decrease (a)
		Input		(In millions)
	Equity-risk premium	6.5	%	$	(0.6	)	$	0.7
	Risk premium	12.9	%	$	(0.2	)	$	0.3
	Size premium	3.8	%	$	(0.3	)	$	0.4
	Growth rate	1	%	$	0.2		$	(0.2	)
	(a) Assuming all other inputs are unchanged.
	Contingent Forward Contract
	On March 28, 2012, the Company entered into a contingent forward contract to purchase Canadian dollars with a notional amount of Cdn$870.0 million to manage the foreign currency exposure with respect to its planned acquisition of Molycorp Canada. The Company accounted for this contingent forward contract at fair value with changes in fair value recognized currently in earnings. Upon settlement of this derivative on June 11, 2012 (Molycorp Canada acquisition date), the Company recognized a loss of $37.6 million, which was reflected in "Other expense" in the consolidated statement of operations and comprehensive income.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Employee Benefit Plans	'
	Employee Benefit Plans and Severance Charges
	Employee Benefit Plans
	Defined Contribution Retirement Plans
	The Company maintains defined contribution retirement plans for all U.S. employees. The Company makes Safe Harbor matching contributions in an amount equal to 100% of the first 3% contributed and 50% of the next 2% contributed by each eligible employee. In addition, the Company may determine to make discretionary matching or nonelective employer (profit sharing) contributions in an amount designated by the Company. Discretionary matching contributions, if any, will be based on a percentage of employee contributions to the defined contribution plans each year, as designated by the Company. The Company's Safe Harbor matching contributions will always be 100% vested. Employees become 100% vested in Company discretionary matching contributions and/or nonelective employer contributions, if any, after 3 years of service.
	Expenses related to this plan totaled $2.9 million, $1.6 million and $1.6 million for the years ended December 31, 2013, 2012 and 2011, respectively. Accrued expenses at December 31, 2013 and 2012 included $1.9 million and $1.4 million related to this plan, respectively.
	Management Incentive Plan (“MIP”)
	On April, 1 2009, the Company established the MIP, which is a nonqualified deferred compensation plan for the purpose of providing deferred compensation benefits for certain members of management. Under the MIP, participants can defer their base salary and other compensation that is supplemental to his or her base salary and is dependent upon achievement of individual or Company performance goals. It is intended that the MIP constitute an unfunded plan for purposes of the Employee Retirement Income Securities Act of 1974, as amended. The amount of compensation or awards deferred is deemed to be invested in a hypothetical investment as of the date of deferral. During the years ended December 31, 2013, 2012 and 2011, the Company funded discretionary contributions to the MIP totaling $0.5 million, $0.4 million and $0.3 million, respectively. In addition, total accrued amount including employee deferrals, discretionary contributions and related earnings was approximately $1.2 million and $0.9 million as of December 31, 2013 and 2012, respectively.
	Bonus Plan
	On November 4, 2010, the Compensation Committee established an annual incentive (“bonus plan”) for all employees that is discretionary in nature. The bonus plan is performance based and includes both qualitative and quantitative criteria. For the years ended December 31, 2013 and 2012, the Company accrued $4.4 million and $3.5 million, respectively.
	Defined Benefit Pension Plan and Other Post-Retirement Benefits
	The Company maintains plans that provide defined pension benefits as well as postretirement medical and life benefits for employees of Molycorp Canada’s former manufacturing facility in Anderson, Indiana. The facility was closed in March 2002, and there were 293 participants in the plans at December 31, 2013. The plans had an aggregate benefit obligation of $7.6 million and $8.9 million as of December 31, 2013 and 2012, respectively, while aggregate assets of the plans totaled $5.6 million as of those dates. The plans’ aggregate underfunded status totaled $2.0 million and $3.3 million as of December 31, 2013 and 2012, respectively, and is included in accumulated other comprehensive income in the consolidated balance sheet, net of related income taxes. The Company’s aggregate net periodic benefit cost totaled $0.3 million and $0.1 million for the year ended December 31, 2013 and for the period from June 12, 2012 to December 31, 2012, respectively.
	As of December 31, 2013, the plans’ assets consisted of fixed income securities of $3.8 million, equity securities of $1.4 million and interest bearing cash of $0.4 million. Of those amounts, $3.6 million of the fixed income securities were valued using Level 2 inputs of the fair value hierarchy while all remaining assets were valued using Level 1 inputs.
	Severance Charges
	In the first quarter of 2013, the Company took a number of actions as part of its continuing effort to contain costs and increase the efficiency of its operations. As a result, the Company reduced a portion of its workforce, primarily within the Corporate group, and recognized employee severance and benefit costs of $2.1 million, which were included in "Selling, general and administrative” expense in the consolidated statements of operations and comprehensive income. As of December 31, 2013, the Company had paid $1.9 million of these severance benefits and expects to pay the remaining benefits by March 31, 2014.
	In relation to the Company’s plan to discontinue operations at the Napanee facility described in Note 27, the Company recognized employee severance and benefit costs of $0.1 million at the beginning of the third quarter of 2013, which were substantially paid as of September 30, 2013. These severance and benefit costs were included in the results of discontinued operations in the consolidated statements of operations and comprehensive income.

Subsidiary_Guarantor_Financial

Subsidiary Guarantor Financial Information	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Subsidiary Guarantor Financial Information	'
	Subsidiary Guarantor Financial Information
	The Senior Notes are jointly, severally and unconditionally guaranteed by all of Molycorp, Inc.'s existing and future domestic material subsidiaries, as defined in the indenture governing the Senior Notes (collectively, the "Guarantor Subsidiaries"). The Senior Notes guarantee of a guarantor will automatically terminate, and the obligations of such guarantor under the Senior Notes guarantee will be unconditionally released and discharged, upon (all terms as defined in the indenture governing the Senior Notes):
	-1	any sale, exchange, transfer or other disposition of a majority of the capital stock of (including by way of consolidation or merger) such guarantor by Molycorp or any restricted subsidiary to any person or persons, as a result of which such guarantor is no longer a direct or indirect subsidiary of Molycorp;
	-2	any sale, exchange, transfer or other disposition of all or substantially all assets of such guarantor that results in such guarantor having no assets;
	-3	the designation by Molycorp of such guarantor as an unrestricted subsidiary; or
	-4	defeasance or discharge of the Senior Notes;
	provided that any such event occurs in accordance with all other applicable provisions of the indenture.
	Presented below are the condensed consolidating financial statements of Molycorp, Inc. (“Parent”) as issuer, its combined guarantor subsidiaries and its combined non-guarantor subsidiaries, which are presented as an alternative to providing separate financial statements for the guarantors. The accounts of the Parent, the guarantor and non-guarantor subsidiaries are presented using the equity method of accounting for investments in subsidiaries for purposes of these condensed consolidating financial statements only. Certain of the prior periods separate financial information has been reclassified to conform to the presentation of the most recent period herein disclosed.
		At December 31, 2013
		(In thousands)
	Condensed Consolidating Balance Sheets	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
	Current assets:
	Cash and cash equivalents	$	169,145		$	6,467		$	138,705		$	—		$	314,317
	Trade accounts receivable, net	—			4,990			56,767			—			61,757
	Inventory	—			32,307			139,476			—			171,783
	Deferred charges	—			—			1,046			—			1,046
	Deferred tax assets	—			—			1,456			—			1,456
	Income tax receivable	—			—			787			—			787
	Prepaid expenses and other current assets	—			15,833			10,088			—			25,921
	Total current assets	169,145			59,597			348,325			—			577,067
	Non-current assets:
	Deposits	1,754			24,243			—			—			25,997
	Property, plant and equipment, net	—			1,620,851			142,023			—			1,762,874
	Inventory	—			25,329			—			—			25,329
	Intangible assets, net	—			442			330,425			—			330,867
	Investments	—			34,134			14,741			—			48,875
	Deferred tax assets	—			—			109			—			109
	Goodwill	—			—			228,750			—			228,750
	Investments in consolidated subsidiaries	532,767			121,849			—			(654,616		)	—
	Intercompany accounts receivable	2,001,583			—			—			(2,001,583		)	—
	Other non-current assets	—			771			6,163			—			6,934
	Total non-current assets	2,536,104			1,827,619			722,211			(2,656,199		)	2,429,735
	Total assets	$	2,705,249		$	1,887,216		$	1,070,536		$	(2,656,199	)	$	3,006,802
	Current liabilities:
	Trade accounts payable	$	—		$	49,702		$	34,747		$	—		$	84,449
	Accrued expenses	18,158			13,782			16,561			—			48,501
	Income tax payable	—			—			1,946			—			1,946
	Deferred tax liabilities	—			—			1,500			—			1,500
	Debt and capital lease obligations	—			2,234			14,128			—			16,362
	Other current liabilities	—			617			—			—			617
	Total current liabilities	18,158			66,335			68,882			—			153,375
	Non-current liabilities:
	Asset retirement obligation	—			16,966			—			—			16,966
	Deferred tax liabilities	—			—			85,481			—			85,481
	Debt and capital lease obligations	1,339,368			19,355			5,193			—			1,363,916
	Derivative liability	—			—			6,089			—			6,089
	Pension liabilities	—			—			2,044			—			2,044
	Intercompany accounts payable	—			1,999,562			2,021			(2,001,583		)	—
	Other non-current liabilities	—			1,393			476			—			1,869
	Total non-current liabilities	1,339,368			2,037,276			101,304			(2,001,583		)	1,476,365
	Total liabilities	$	1,357,526		$	2,103,611		$	170,186		$	(2,001,583	)	$	1,629,740
	Stockholders’ equity:
	Common stock	241			—			—			—			241
	Preferred stock	2			—			—			—			2
	Additional paid-in capital	2,194,405			149,857			1,315,426			(1,465,283		)	2,194,405
	Accumulated other comprehensive loss	(6,451		)	—			(6,451		)	6,451			(6,451		)
	Accumulated deficit	(840,474		)	(366,252		)	(437,964		)	804,216			(840,474		)
	Total Molycorp stockholders’ equity	1,347,723			(216,395		)	871,011			(654,616		)	1,347,723
	Noncontrolling interests	—			—			29,339			—			29,339
	Total stockholders’ equity	1,347,723			(216,395		)	900,350			(654,616		)	1,377,062
	Total liabilities and stockholders’ equity	$	2,705,249		$	1,887,216		$	1,070,536		$	(2,656,199	)	$	3,006,802
		At December 31, 2012
		(In thousands)
Condensed Consolidating Balance Sheets	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
Current assets:
Cash and cash equivalents	$	16,560		$	18,020		$	193,210		$	—		$	227,790
Trade accounts receivable, net	—			7,738			44,692			—			52,430
Inventory	—			49,416			237,960			—			287,376
Deferred charges	—			2,203			7,209			—			9,412
Deferred tax assets	—			—			11,731			(1,942		)	9,789
Income tax receivable	—			25,087			—			—			25,087
Prepaid expenses and other current assets	—			9,085			12,709			—			21,794
Total current assets	16,560			111,549			507,511			(1,942		)	633,678
Non-current assets:
Deposits	1,752			24,862			155			—			26,769
Property, plant and equipment, net	—			1,377,147			167,157			—			1,544,304
Inventory	—			26,096			—			—			26,096
Intangible assets, net	—			508			450,430			—			450,938
Investments	—			45,241			18,795						64,036
Deferred tax assets	6,030			—			—			(6,030		)	—
Goodwill	—			—			239,742			—			239,742
Investments in consolidated subsidiaries	883,319			97,960			—			(981,279		)	—
Intercompany accounts receivable	1,539,877			207,035			794			(1,747,706		)	—
Other non-current assets	—			885			6,087			—			6,972
Total non-current assets	2,430,978			1,779,734			883,160			(2,735,015		)	2,358,857
Total assets	$	2,447,538		$	1,891,283		$	1,390,671		$	(2,736,957	)	$	2,992,535
Current liabilities:
Trade accounts payable	$	—		$	191,769		$	50,225		$	—		$	241,994
Accrued expenses	14,872			10,087			34,054			—			59,013
Income tax payable	—			—			15,267			—			15,267
Deferred tax liabilities	—			1,942			—			(1,942		)	—
Debt and capital lease obligations	—			352			39,252			—			39,604
Other current liabilities	—			3,539			—			—			3,539
Total current liabilities	14,872			207,689			138,798			(1,942		)	359,417
Non-current liabilities:
Asset retirement obligation	—			18,586			—			—			18,586
Deferred tax liabilities	—			23,130			143,575			(6,030		)	160,675
Debt and capital lease obligations	1,166,777			15,163			6,892			—			1,188,832
Derivative liability	—			—			7,816			—			7,816
Pension liabilities	—			—			3,292			—			3,292
Intercompany accounts payable	49,843			1,577,363			120,500			(1,747,706		)	—
Other non-current liabilities	—			1,102			1,557			—			2,659
Total non-current liabilities	1,216,620			1,635,344			283,632			(1,753,736		)	1,381,860
Total liabilities	$	1,231,492		$	1,843,033		$	422,430		$	(1,755,678	)	$	1,741,277
Stockholders’ equity:
Common stock	139			—			—			—			139
Preferred stock	2			—			—			—			2
Additional paid-in capital	1,691,429			149,857			1,283,863			(1,433,720		)	1,691,429
Accumulated other comprehensive loss	(9,433		)	—			(9,433		)	9,433			(9,433		)
Accumulated deficit	(466,091		)	(101,607		)	(341,401		)	443,008			(466,091		)
Total Molycorp stockholders’ equity	1,216,046			48,250			933,029			(981,279		)	1,216,046
Noncontrolling interests	—			—			35,212			—			35,212
Total stockholders’ equity	1,216,046			48,250			968,241			(981,279		)	1,251,258
Total liabilities and stockholders’ equity	$	2,447,538		$	1,891,283		$	1,390,671		$	(2,736,957	)	$	2,992,535
	Year Ended December 31, 2013
	(In thousands)
Condensed Consolidating Statements of Operations and Comprehensive Income	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
Revenues	$	—		$	88,266		$	517,202		$	(51,078	)	$	554,390
Costs of sales:
Costs excluding depreciation and amortization	—			(200,650		)	(404,259		)	51,078			(553,831		)
Depreciation and amortization	—			(40,220		)	(27,507		)	—			(67,727		)
Gross (loss) profit	—			(152,604		)	85,436			—			(67,168		)
Operating expenses:
Selling, general and administrative	(190		)	(66,132		)	(40,847		)	—			(107,169		)
Corporate development	—			(247		)	—			—			(247		)
Depreciation, amortization and accretion	—			(6,424		)	(31,613		)	—			(38,037		)
Research and development	—			(5,069		)	(18,103		)	—			(23,172		)
Impairment of goodwill and other long-lived assets	—			(14,250		)	(106,648		)	—			(120,898		)
Operating loss	(190		)	(244,726		)	(111,775		)	—			(356,691		)
Other (expense) income:
Other expense	5			(7,242		)	(288		)	—			(7,525		)
Foreign exchange (losses) gains, net	(9,896		)	11			9,509			—			(376		)
Interest (expense) income, net	(64,392		)	3,807			(7,099		)	—			(67,684		)
Interest income (expense) from intercompany notes	36,724			(2,493		)	(34,231		)	—			—
Equity earnings from consolidated subsidiaries	(330,604		)	(7,674		)	—			338,278			—
	(368,163		)	(13,591		)	(32,109		)	338,278			(75,585		)
Loss from continuing operations before income taxes and equity earnings	(368,353		)	(258,317		)	(143,884		)	338,278			(432,276		)
Income tax (loss) benefit	(6,030		)	23,130			53,843			—			70,943
Equity in results of affiliates	—			(6,529		)	(2,640		)	—			(9,169		)
Loss from continuing operations	(374,383		)	(241,716		)	(92,681		)	338,278			(370,502		)
Loss from discontinued operations, net of tax	—			—			(6,427		)	—			(6,427		)
Net loss	(374,383		)	(241,716		)	(99,108		)	338,278			(376,929		)
Net income attributable to noncontrolling interest	—			—			2,546			—			2,546
Net loss attributable to Molycorp stockholders	$	(374,383	)	$	(241,716	)	$	(96,562	)	$	338,278		$	(374,383	)
Net loss	$	(374,383	)	$	(241,716	)	$	(99,108	)	$	338,278		$	(376,929	)
Other comprehensive income:
Foreign currency translation adjustments	$	—		$	—		$	1,623		$	—		$	1,623
Actuarial gain (loss)	—			—			1,359			—			1,359
Comprehensive loss	$	(374,383	)	$	(241,716	)	$	(96,126	)	$	338,278		$	(373,947	)
Comprehensive loss attributable to:
Molycorp stockholders	(374,383		)	(241,716		)	(98,672		)	338,278			(376,493		)
Noncontrolling interest	—			—			2,546			—			2,546
	$	(374,383	)	$	(241,716	)	$	(96,126	)	$	338,278		$	(373,947	)
	Year Ended December 31, 2012
	(In thousands)
Condensed Consolidating Statements of Operations and Comprehensive Income	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
Revenues	$	—		$	139,257		$	413,951		$	(25,512	)	$	527,696
Costs of sales:
Costs excluding depreciation and amortization	—			(153,461		)	(350,304		)	25,512			(478,253		)
Depreciation and amortization	—			(12,094		)	(18,527		)	—			(30,621		)
Gross (loss) profit	—			(26,298		)	45,120			—			18,822
Operating expenses:
Selling, general and administrative	46			(86,493		)	(26,990		)	—			(113,437		)
Corporate development	(46		)	(19,750		)	—			—			(19,796		)
Depreciation, amortization and accretion	—			(2,220		)	(19,967		)	—			(22,187		)
Research and development	—			(12,984		)	(14,812		)	—			(27,796		)
Impairment of goodwill and other long-lived assets	—			(5,747		)	(296,008		)	—			(301,755		)
Operating loss	—			(153,492		)	(312,657		)	—			(466,149		)
Other (expense) income:
Other expense	(37,589		)	(328		)	(881		)	—			(38,798		)
Foreign exchange gains, net	—			—			2,872			—			2,872
Interest expense, net	(18,118		)	(3,496		)	(502		)	—			(22,116		)
Interest income (expense) from intercompany notes	25,157			3,152			(28,309		)	—			—
Equity earnings from consolidated subsidiaries	(456,649		)	(23,205		)	—			479,854			—
	(487,199		)	(23,877		)	(26,820		)	479,854			(58,042		)
Loss from continuing operations before income taxes and equity earnings	(487,199		)	(177,369		)	(339,477		)	479,854			(524,191		)
Income tax benefit (expense)	6,030			53,840			(5,795		)	—			54,075
Equity in results of affiliates	—			(2,439		)	(1,051		)	—			(3,490		)
Loss from continuing operations	(481,169		)	(125,968		)	(346,323		)	479,854			(473,606		)
Loss from discontinued operations, net of tax	—			—			(1,737		)	—			(1,737		)
Net loss	(481,169		)	(125,968		)	(348,060		)	479,854			(475,343		)
Net income attributable to noncontrolling interest	—			—			(5,826		)	—			(5,826		)
Net loss attributable to Molycorp stockholders	$	(481,169	)	$	(125,968	)	$	(353,886	)	$	479,854		$	(481,169	)
Net loss	$	(481,169	)	$	(125,968	)	$	(348,060	)	$	479,854		$	(475,343	)
Other comprehensive income:
Foreign currency translation adjustments	—			—			248			—			248
Actuarial gain (loss)	—			—			(1,200		)	—			(1,200		)
Comprehensive loss	$	(481,169	)	$	(125,968	)	$	(349,012	)	$	479,854		$	(476,295	)
Comprehensive loss attributable to:
Molycorp stockholders	(481,169		)	(125,968		)	(343,186		)	479,854			(470,469		)
Noncontrolling interest	—			—			(5,826		)	—			(5,826		)
	$	(481,169	)	$	(125,968	)	$	(349,012	)	$	479,854		$	(476,295	)
	Year Ended December 31, 2011
	(In thousands)
Condensed Consolidating Statements of Operations and Comprehensive Income	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
Revenues	$	—		$	365,490		$	100,398		$	(69,057	)	$	396,831
Costs of sales:
Costs excluding depreciation and amortization	—			(158,951		)	(74,457		)	69,057			(164,351		)
Depreciation and amortization	—			(9,411		)	(4,128		)	—			(13,539		)
Gross profit	—			197,128			21,813			—			218,941
Operating expenses:
Selling, general and administrative	(7		)	(48,296		)	(2,454		)	—			(50,757		)
Corporate development	—			(5,912		)	—			—			(5,912		)
Depreciation, amortization and accretion	—			(1,378		)	(310		)	—			(1,688		)
Research and development	—			(7,718		)	—			—			(7,718		)
Operating (loss) income	(7		)	133,824			19,049			—			152,866
Other (expense) income:
Other expense	—			(153		)	—			—			(153		)
Foreign exchange losses, net	—			—			(5,415		)	—			(5,415		)
Interest (expense) income, net	(499		)	248			(137		)	—			(388		)
Interest income (expense) from intercompany notes	424			(296		)	(128		)	—			—
Equity earnings from consolidated subsidiaries	117,608			12,485			—			(130,093		)	—
	117,533			12,284			(5,680		)	(130,093		)	(5,956		)
Income before income taxes	117,526			146,108			13,369			(130,093		)	146,910
Income tax expense	—			(28,500		)	(76		)	—			(28,576		)
Net income	117,526			117,608			13,293			(130,093		)	118,334
Net income attributable to noncontrolling interest	—			—			(808		)	—			(808		)
Net income attributable to Molycorp stockholders	$	117,526		$	117,608		$	12,485		$	(130,093	)	$	117,526
Net income	$	117,526		$	117,608		$	13,293		$	(130,093	)	$	118,334
Other comprehensive income:
Foreign currency translation adjustments	—			—			(8,481		)	—			(8,481		)
Comprehensive income	$	117,526		$	117,608		$	4,812		$	(130,093	)	$	109,853
Comprehensive income attributable to:
Molycorp stockholders	117,526			117,608			4,427			(130,093		)	109,468
Noncontrolling interest	—			—			385			—			385
	$	117,526		$	117,608		$	4,812		$	(130,093	)	$	109,853
	Year Ended December 31, 2013
	(In thousands)
Condensed Consolidating Statements of Cash Flows	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
Net cash (used in) provided by operating activities	$	(39,075	)	$	(133,612	)	$	18,336		$	—		$	(154,351	)
Cash flows from investing activities:
Loans to guarantor	—			—			(40,000		)	40,000			—
Loans to Parent	—			—			(12,800		)	12,800			—
Intercompany advances made	(391,560		)	—			—			391,560			—
Loans to non-guarantor	(117,512		)	(1,300		)	—			118,812			—
Repayments of notes receivable from non-guarantor	38,000			117,776			—			(155,776		)	—
Investment in joint ventures	—			(3,423		)	—			—			(3,423		)
Capital expenditures	—			(361,782		)	(17,530		)	—			(379,312		)
Other investing activities	—			4,902			575			—			5,477
Net cash used in investing activities	(471,072		)	(243,827		)	(69,755		)	407,396			(377,258		)
Cash flows from financing activities:
Repayments of debt	—			—			(26,823		)	—			(26,823		)
Net proceeds from sale of common stock	495,717			—			—			—			495,717
Issuance of 5.50% Convertible Notes	165,600			—			—			—			165,600
Payments of preferred dividends	(11,385		)	—			—			—			(11,385		)
Dividend paid to noncontrolling interests	—			—			(4,546		)	—			(4,546		)
Borrowing from non-guarantor	12,800			40,000			—			(52,800		)	—
Borrowings from parent	—			—			117,512			(117,512		)	—
Borrowings from guarantor	—			—			1,300			(1,300		)	—
Repayments to parent	—			—			(38,000		)	38,000			—
Repayments to guarantor	—			—			(117,776		)	117,776			—
Intercompany advances owed	—			327,183			64,377			(391,560		)	—
Other financing activities	—			(1,297		)	—			—			(1,297		)
Net cash provided by financing activities	662,732			365,886			(3,956		)	(407,396		)	617,266
Effect of exchange rate changes on cash	—			—			870			—			870
Net change in cash and cash equivalents	152,585			(11,553		)	(54,505		)	—			86,527
Cash and cash equivalents at beginning of the period	16,560			18,020			193,210			—			227,790
Cash and cash equivalents at end of period	$	169,145		$	6,467		$	138,705		$	—		$	314,317
	Year Ended December 31, 2012
	(In thousands)
Condensed Consolidating Statements of Cash Flows	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
Net cash (used in) provided by operating activities	$	(13,207	)	$	(112,386	)	$	35,958		$	—		$	(89,635	)
Cash flows from investing activities:
Cash paid in connection with acquisitions, net of cash acquired	—			—			(591,011		)	—			(591,011		)
Loans to subsidiaries	(683,063		)	—			—			683,063			—
Loans to Parent	—			(37,589		)	—			37,589			—
Intercompany advances made	(1,009,014		)	—			—			1,009,014			—
Repayments from subsidiaries	87,824			—			—			(87,824		)	—
Investment in subsidiaries	(350,000		)	—			—			350,000			—
Notes receivable to non-guarantor	—			(227,512		)	—			227,512			—
Repayments of notes receivable from non-guarantor	—			110,000			—			(110,000		)	—
Investment in joint ventures	—			(27,680		)	(5,364		)	—			(33,044		)
Deposits	—			(3,999		)	—			—			(3,999		)
Capital expenditures	—			(766,951		)	(24,518		)	—			(791,469		)
Acquisition of exploration rights	—			—			(8,167		)	—			(8,167		)
Other investing activities	—			—			4,761			—			4,761
Net cash used in investing activities	(1,954,253		)	(953,731		)	(624,299		)	2,109,354			(1,422,929		)
Cash flows from financing activities:
Capital contributions from stockholder	390,093			—			—			—			390,093
Capital contributions from Parent	—			—			350,000			(350,000		)	—
Repayments of debt	—			(870		)	(227,838		)	—			(228,708		)
Net proceeds from sale of common stock	132,130			—			—			—			132,130
Issuance of 10% Senior Secured Notes	635,373			—			—			—			635,373
Issuance of 6.00% Convertible Notes	395,712			—			—			—			395,712
Payments of preferred dividends	(11,385		)	—			—			—			(11,385		)
Dividend paid to noncontrolling interests	—			—			(5,977		)	—			(5,977		)
Proceeds from debt	—			—			14,699			—			14,699
Borrowings from parent	—			227,512			455,551			(683,063		)	—
Repayments of borrowings to parent	—			(34,327		)	(53,497		)	87,824			—
Borrowing from guarantor	37,589			—			227,512			(265,101		)	—
Repayments of borrowings to guarantor	—			—			(110,000		)	110,000			—
Intercompany advances owed	—			881,179			127,835			(1,009,014		)	—
Other financing activities	(2,938		)	(115		)	1,499			—			(1,554		)
Net cash provided by financing activities	1,576,574			1,073,379			779,784			(2,109,354		)	1,320,383
Effect of exchange rate changes on cash	—			—			1,116			—			1,116
Net change in cash and cash equivalents	(390,886		)	7,262			192,559			—			(191,065		)
Cash and cash equivalents at beginning of the period	407,446			10,758			651			—			418,855
Cash and cash equivalents at end of period	$	16,560		$	18,020		$	193,210		$	—		$	227,790
	Year Ended December 31, 2011
	(In thousands)
Condensed Consolidating Statements of Cash Flows	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
Net cash provided by (used in) operating activities	$	903		$	44,211		$	(2,149	)	$	—		$	42,965
Cash flows from investing activities:
Cash paid in connection with acquisitions, net of cash acquired	—			(30,128		)	105			—			(30,023		)
Cash paid to acquire non-marketable securities	—			(20,000		)	—			—			(20,000		)
Loans to subsidiaries	(49,430		)	—			—			49,430			—
Intercompany advances made	(290,633		)	—			—			290,633			—
Deposits	16,449			(13,552		)	—			—			2,897
Capital expenditures	—			(294,010		)	(8,170		)	—			(302,180		)
Other investing activities	—			16			(100		)	—			(84		)
Net cash used in investing activities	(323,614		)	(357,674		)	(8,165		)	340,063			(349,390		)
Cash flows from financing activities:
Repayments of short-term borrowings—related party	—			(3,150		)	—			—			(3,150		)
Repayments of debt	—			—			(4,428		)	—			(4,428		)
Net proceeds from sale of preferred stock	199,642			—			—			—			199,642
Net proceeds from sale of Convertible Notes	223,100			—			—			—			223,100
Payments of preferred dividends	(9,015		)	—			—			—			(9,015		)
Proceeds from debt	—			—			5,131			—			5,131
Intercompany advances owed	—			290,001			632			(290,633		)	—
Net borrowings from parent	—			37,370			12,060			(49,430		)	—
Net cash provided by financing activities	413,727			324,221			13,395			(340,063		)	411,280
Effect of exchange rate changes on cash	—			—			(2,430		)	—			(2,430		)
Net change in cash and cash equivalents	91,016			10,758			651			—			102,425
Cash and cash equivalents at beginning of the period	316,430			—			—			—			316,430
Cash and cash equivalents at end of period	$	407,446		$	10,758		$	651		$	—		$	418,855

Discontinued_Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Discontinued Operations
	In July 2013, the Company committed to a plan to discontinue operations at its Napanee facility by the end of 2013 due to a declining demand for rhenium combined with unfavorable operating costs in this particular recycling sector. In December of 2013, the Company received a firm offer to purchase the Napanee facility. The facility, which consists of two buildings on approximately two acres, specializes on the recycling of rhenium bearing scrap, was acquired in June 2012 as part of the Molycorp Canada acquisition and is included within the Rare Metals segment. In addition to the land and the buildings, the disposal group includes hydrometallurgical recovery equipment and rhenium inventory. As of December 31, 2013, the disposal group had the following carrying amounts, which were recorded under “Prepaid expenses and other current assets” in the consolidated balance sheet:
		31-Dec-13
		(In thousands)
	Land	$	25
	Buildings	250
	Equipment	250
	Inventory	475
	Carrying value of disposal group	$	1,000
	The following table summarizes the operating results of the Napanee facility included in discontinued operations for the years ended December 31, 2013 and 2012:
		December 31,			June 12 -December 31,
		2013			2012
		(In thousands)
	Revenues	$	2,091		$	1,214
	Costs of sales	(3,834		)	(2,691		)
	Selling, general and administrative expenses	(351		)	(232		)
	Depreciation	(28		)	(28		)
	Operating loss	(2,122		)	(1,737		)
	Loss on assets impairment	(4,305		)	—
	Income tax	—			—
	Net loss	$	(6,427	)	$	(1,737	)

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	For assets and liabilities that are required under GAAP to be measured at fair value on a recurring or nonrecurring basis, the Company refers to a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into the following three broad levels:
	•	Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.
	•	Level 2 - Observable inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data by correlation or other means.
	•	Level 3 - Prices or valuation techniques requiring inputs that are both significant to the fair value measurement and unobservable.
	The fair value of many of the Company's financial instruments, including cash and cash equivalents, trade accounts receivables, trade accounts payable and accrued expenses approximate their related carrying amounts because of the relatively short-term nature of these financial instruments.
	The Company's assets and liabilities measured at fair value on a recurring basis were as follows at December 31, 2013 and 2012:
		At December 31, 2013
		Quoted Prices in Active Markets for Identical Assets/Liabilities			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)				Total
		(In thousands)
	Assets:
	Cash equivalents	$	179,052		—			—				$	179,052
	Liabilities:
	Derivative liability	—			—			$	6,089			$	6,089
		At December 31, 2012
		Quoted Prices in Active Markets for Identical Assets/Liabilities			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)				Total
		(In thousands)
	Assets:
	Cash equivalents	$	58,253		—			—				$	58,253
	Liabilities:
	Derivative liability	—			—			$	7,816			$	7,816
	The financial assets classified in Level 1 at December 31, 2013 and 2012 consist of money market funds valued based on quoted prices for identical assets in active markets. The technique used to fair value the derivative liability classified in Level 3 is the income approach based on a discounted cash flow model. See Note 24 for further information of the derivative liability.
	The following table presents the fair value of financial liabilities the Company reports at their carrying value:
			At December 31, 2013							At December 31, 2012
		Classification	Carrying Value			Fair Value				Carrying Value				Fair Value
			(In thousands)
	Long-term debt
	3.25% Convertible Notes due June 2016	(Level 1)	$	207,028		$	161,771			$	198,689			$	159,542
	6.00% Convertible Notes due September 2017	(Level 1)	346,708			312,570				331,977				412,965
	5.50% Convertible Notes due February 2018	(Level 1)	148,198			164,015				n/a				n/a
	10% Senior Secured Notes due June 2020	(Level 1)	637,435			646,750				636,111				n/a
	Total long-term debt		$	1,339,369		$	1,285,106			$	1,166,777			$	572,507
	The fair value of the long-term debt listed above is based on the last available market trade of each year. Unlike the convertible notes, the Senior Notes are more actively traded and, therefore, their market yield is generally available through the last business day of December. The Debentures are not actively traded, and the difference between their carrying value and fair value is impractical to estimate.
	The carrying amount of certain other financial instruments, such as trade accounts receivables, trade accounts payable and accrued expenses approximate fair value because of their relatively short-term nature, and, therefore, have been excluded from the table above.

Unaudited_Supplementary_Data

Unaudited Supplementary Data	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Unaudited Supplementary Data	'
	Unaudited Supplementary Data
	The following is a summary of the selected quarterly financial information (unaudited):
		2013
		Quarter ended
		31-Mar		30-Jun		30-Sep		31-Dec
		(In thousands of dollars, except per share data)
	Revenues	145,398		136,112		149,066		123,814
	Gross profit (loss)	(4,305	)	(18,036	)	(17,778	)	(27,049	)
	Loss from continuing operations before income taxes and equity earnings (a)	(57,249	)	(70,254	)	(76,181	)	(228,592	)
	Net loss	(38,153	)	(70,689	)	(69,799	)	(198,288	)
	Net loss attributable to Molycorp stockholders	(38,971	)	(71,175	)	(69,929	)	(194,308	)
	Loss per share of common stock from continuing operations: (b)
	Basic	(0.27	)	(0.44	)	(0.43	)	(0.95	)
	Diluted	(0.27	)	(0.44	)	(0.43	)	(0.95	)
		2012
		Quarter ended
		31-Mar		30-Jun		30-Sep		31-Dec
		(In thousands of dollars, except per share data)
	Revenues	84,470		104,410		205,205		133,611
	Gross profit (loss)	31,027		(3,996	)	11,494		(19,703	)
	Loss from continuing operations before income taxes and equity earnings (c)	(5,434	)	(93,871	)	(42,984	)	(381,902	)
	Net loss	(3,478	)	(66,924	)	(15,451	)	(389,490	)
	Net loss attributable to Molycorp stockholders	(3,478	)	(67,604	)	(18,891	)	(391,196	)
	Loss per share of common stock from continuing operations: (b)
	Basic	(0.07	)	(0.71	)	(0.19	)	(3.16	)
	Diluted	(0.07	)	(0.71	)	(0.19	)	(3.16	)
	(a)	Includes the following impairment charges in the fourth quarter: goodwill, $11.0 million; rare earths quotas, $67.2 million; patents, $10.2 million; exploration rights, $16.2 million; cost-method investments $9.4 million and long-lived tangible assets, $16.3 million.
	(b)	The sum of the quarterly income (loss) per share may be different than the per share amount for the year as the calculation for each quarter is based on the weighted average shares outstanding for that period.
	(c)	Includes the following impairment charges in the fourth quarter: goodwill, $287.9 million; patents, $6.0 million; and long-lived tangible assets, $5.9 million.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	Preferred stock dividend
	On February 5, 2014, the Company declared a cash dividend of $1.375 per share on the Convertible Preferred Stock to be paid on March 1, 2014 to holders of record at the close of business on February 15, 2014.
	Mandatory convertible preferred stock
	The Company's mandatory convertible preferred stock converted into 4,140,000 shares of common stock as of March 1, 2014.
	Sale of Napanee facility
	On March 3, 2014, the Company closed the sale of its Napanee facility.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Use of Estimates	'
	Use of Estimates
	The preparation of the Company's consolidated financial statements, in accordance with generally accepted accounting principles in the United States of America (“GAAP”), requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases its estimates on the Company’s historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ significantly from these estimates under different assumptions and conditions.
	Significant estimates made by management in the accompanying financial statements include: the collectability of accounts receivable; the realizability of inventory; the useful lives and recoverability of long-lived assets such as property, plant and equipment, capital leases, intangible assets, including goodwill, and investments; the determination of uncertain tax positions; the fair values of assets acquired and liabilities assumed in business combinations; and the adequacy of the asset retirement obligation.
Basis of Presentation	'
	Basis of Presentation
	The consolidated financial statements include the accounts of Molycorp and its majority-owned subsidiaries where it exerts control. Investments in which Molycorp does not have control and is not considered to be the primary beneficiary of a variable interest entity, but it exercises significant influence over the operating and financial policies of the investee, are accounted for using the equity method of accounting. All other investments are accounted for using the cost method of accounting. All intercompany balances and transactions are eliminated in consolidation.
	Prior period amounts of "Other comprehensive income (loss)" in the consolidated statements of operations and comprehensive income, and certain prior period adjustments to reconcile net (loss) income to net cash from operating activities in the consolidated statements of cash flows have been reclassified to conform to the current period presentation. Such reclassifications did not affect results of operations.
Revenues and Costs of Sales	'
	Revenues and Costs of Sales
	Revenues are recognized when persuasive evidence of an arrangement exists, the risks and rewards of ownership have been transferred to the customer, which is generally when title passes, the selling price is fixed or determinable, and collection is reasonably assured. Title generally passes to the customer upon shipment of product from the Company’s facilities. Prices are generally set at the time of, or prior to, shipment. Transportation and distribution costs are incurred only on sales for which the Company is responsible for delivering the product.
	Costs of sales include costs of production and write downs of inventory to net realizable value. Primary production costs include labor, raw materials, depreciation, supplies, maintenance costs and plant overhead.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash and liquid investments with an original maturity of three months or less. Because of the short maturity of these investments, the carrying amounts approximate their fair values.
Trade Accounts Receivable	'
	Trade Accounts Receivable
	Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The Company reviews the need for an allowance for doubtful accounts quarterly based on historical experience with each customer and the specifics of each arrangement.
Inventories	'
	Inventory
	Inventory consists of stockpiles of crushed ore, bastnasite concentrate, raw materials, work in process, finished goods and materials and supplies. Inventory cost is determined using the lower of weighted average cost or estimated net realizable value, and includes all expenses directly attributable to the manufacturing process as well as production overheads based on normal operating capacity. The Company evaluates the carrying value of inventory each quarter giving consideration to slow-moving items, obsolescence, excessive levels, and other factors and recognizes related write-downs as necessary. Write-downs of inventory to estimated net realizable value are charged to costs of sales. Inventory expected to be used and sold beyond a twelve-month period is classified as a non-current asset in the consolidated balance sheets.
Property, Plant and Equipment	'
	Property, Plant and Equipment
	Property, plant and equipment obtained in business acquisitions are recorded at their estimated fair value as of the acquisition date. Expenditures for new property, plant and equipment, and improvements that extend the useful life or functionality of the asset are recorded at their cost of acquisition or construction. Depreciation on plant and equipment is provided using the straight-line method over their estimated useful lives (buildings and improvements - generally 4 to 40 years; plant and equipment - 2 to 15 years). Maintenance costs are expensed as incurred.
	Construction in progress includes costs directly attributable to the construction or development of long-term tangible assets. These costs may include: labor and employee benefits associated with the construction of the asset; site preparation; permitting; engineering; installation and assembly; procurement; insurance; legal; commissioning; and interest on borrowings to finance the construction of the asset. Depreciation is not recorded on the related assets until they are placed in service or ready for their intended use.
	Gains or losses arising on the disposal of property, plant and equipment are determined as the difference between the proceeds from disposal and the carrying amount of the asset, and are included in other income (expense) in the consolidated statements of operations and comprehensive income.
Mineral Properties and Development Costs	'
	Mineral Properties and Development Costs
	Mineral properties and development costs, which are referred to collectively as mineral properties, include acquisition costs, drilling costs, and the cost of other development work, all of which are capitalized. The Company depletes mineral properties using the units of production method over estimated proven and probable reserves. Proven and probable reserves are based on extensive drilling, sampling, mine modeling, and mineral recovery from which economic feasibility has been determined, and are estimated based on information available at the time the reserves are calculated. Proven and probable reserves are based on estimates, and no assurance can be given that the indicated levels of rare earths will be realized or that production costs and estimated future development costs will not exceed the net realizable value of the products. Reserve estimates may require revisions based on actual production experience. Market price fluctuations of rare earths, as well as increased production costs or reduced recovery rates, could render proven and probable reserves containing relatively lower grades of mineralization uneconomic to exploit and might result in a reduction of reserves. Depletion expense is an inventoriable cost.
Intangible Assets	'
	Intangible Assets
	Intangible assets consist primarily of customer relationships, Chinese rare earths quotas, patents, Chinese land use rights and both indefinite-lived and finite-lived trade names. The Chinese rare earths quotes were written off in December 2013. Finite-lived intangible assets are amortized on a straight-line basis over the estimated useful lives. Useful lives of the Company's finite-lived intangible assets currently range from 2 to 16 years for customer relationships, patents and trade name, and 50 years for Chinese land use rights.
Recoverability of Long-Lived Depreciable Amortizable Assets	'
	Recoverability of Long-Lived Depreciable/Amortizable Assets
	Long-lived assets such as property, plant, and equipment, mineral properties and intangible assets that are depreciated or amortized, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. An impairment is considered to exist if the total undiscounted future cash flows expected from the use of the asset or asset group are less than its carrying amount. An impairment loss, if any, is recorded for the excess of the asset's or asset group's carrying value over its fair value, as determined by a valuation technique appropriate to the given circumstances.
Recoverability of Goodwill	'
	Recoverability of Goodwill
	The Company assigns goodwill arising from acquired companies to the reporting units that are expected to benefit from the acquisition. On an annual basis or in interim periods when circumstances require, the Company tests the recoverability of its goodwill utilizing a two-step impairment analysis. Under this analysis, the Company initially compares the fair value of each identified reporting unit with the reporting unit's carrying value. The Company's reporting units are determined either at the operating segment level or a component one level below the operating segment that constitutes a business for which the operating segment's management generally reviews production and financial results. To the extent that a reporting unit's fair value is less than its carrying value, the Company performs an additional step to determine the implied fair value of the reporting unit's goodwill. The implied fair value of goodwill is calculated by first allocating the reporting unit's fair value to its assets and liabilities, excluding goodwill, and then comparing the excess of the reporting unit's fair value to the carrying value of goodwill. To the extent that the carrying value of goodwill exceeds its implied fair value, the Company would recognize an impairment loss. The valuation methodology utilized to determine the fair value of the Company's reporting units is based on a discounted cash flow model, or income approach, in which expected future net cash flows, excluding any financing costs or dividends, are discounted using an appropriate discount rate. The income approach is dependent upon a number of significant management estimates about future performance including expected sales volumes, sales prices, production costs, income taxes, capital expenditures, working capital changes, foreign exchange rates and the after-tax weighted average cost of capital. Changes in any of these assumptions could materially impact the estimated fair value of the Company's reporting units. Discount factors are determined individually for each reporting unit to reflect its respective risk profile as assessed by the Company's management.
Investments	'
	Investments
	Investments in non-marketable equity securities of entities in which the Company has the ability to exercise significant influence over the entity's operating and financial policies are accounted for by the equity method. The Company recognizes its proportionate share of the entity’s income or loss each period with such amounts included in "Equity in results of affiliate" in the consolidated statements of operations and comprehensive income. Equity method investments are reviewed periodically for other-than-temporary decline in value. Investments in non-marketable equity securities of entities for which the Company does not have the ability to exercise significant influence over the entity’s operations and financial policies are accounted for by the cost method. Cost method investments are carried at cost and are subject to other-than-temporary impairment assessments.
Business Combinations	'
	Business Combinations
	The Company accounts for all business combinations using the acquisition method of accounting. Under this method, assets and liabilities, including any noncontrolling interests, are recognized at fair value at the date of acquisition. The excess of the purchase price over the fair value of assets acquired, net of liabilities assumed, and noncontrolling interests is recognized as goodwill. Certain adjustments to the assessed fair values of the assets, liabilities, or noncontrolling interests made subsequent to the acquisition date, but within the measurement period, which is up to one year, are recorded as adjustments to goodwill. Any adjustments subsequent to the measurement period are recorded in income. Any cost or equity method interest that the Company holds in the acquired company prior to the acquisition is remeasured to fair value at acquisition with a resulting gain or loss recognized in income for the difference between fair value and the existing book value. Results of operations of the acquired entity are included in the Company’s results from the date of the acquisition. The Company expenses all costs as incurred related to an acquisition under “Corporate development” in the consolidated statement of operations and comprehensive income.
Asset Retirement Obligation	'
	Asset Retirement Obligation
	The Company accounts for reclamation costs, along with other costs related to the closure of the Molycorp Mountain Pass facility, in accordance with ASC 410-20, Asset Retirement Obligations, which requires the Company to recognize asset retirement obligations at estimated fair value in the period in which the obligation is incurred. Events that trigger the recognition of asset retirement obligations include land disturbance and construction of properties for which there is a legal obligation to restore the property to its original state. The liability is initially measured at fair value using a discounted cash flow model, and is subsequently adjusted for accretion expense and changes in the amount or timing of the estimated cash flows. A corresponding asset retirement cost is capitalized as part of the carrying amount of the related long-lived assets and is depreciated over the assets’ remaining useful lives.
Income Taxes	'
	Income Taxes
	The Company accounts for income taxes in accordance with Accounting Standard Codification 740, Income Taxes, which requires that deferred tax assets and liabilities be recognized for the tax effect of temporary differences between the financial statement and tax basis of recorded assets and liabilities at enacted statutory tax rates. This guidance also requires that deferred tax assets be reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax assets will not be realized based on both our historical and anticipated earnings levels. The Company reviews its deferred tax assets each reporting period to determine if adjustments to the valuation allowance are necessary.
	The Company records its deferred tax assets and liabilities using enacted tax rates expected to apply to taxable income for the period in which the deferred tax assets or liabilities are expected to be realized. The statutory income tax rates that are applied to the current and deferred income tax calculations differ by the jurisdictions in which the Company conducts business. Changes in such income tax rates and apportionment laws may result in changes in the Company’s deferred income tax assets, liabilities and related expense in the period of enactment.
Foreign Currency	'
	Foreign Currency
	The functional currency of the majority of the Company's operations is the U.S. dollar. Assets and liabilities recorded in functional currencies other than U.S. dollars are translated at the spot rate in effect at the applicable reporting date; revenues and expenses in foreign currencies are translated at actual exchange rates for significant transactions or at the average exchange rates in effect during the applicable period. The resulting unrealized cumulative translation adjustment is recorded as a component of "Accumulated other comprehensive income (loss)" in the consolidated balance sheets. The effect of exchange rates on cash balances held in foreign currencies are separately reported in the Company’s consolidated statements of cash flows.
	Transactions denominated in currencies other than the applicable functional currency are recorded based on exchange rates at the time such transactions occur. Changes in exchange rates associated with amounts recorded in the Company’s consolidated balance sheets related to these non-functional currency transactions result in transaction gains and losses that are reflected in "Foreign exchange gains (losses), net" in the consolidated statements of operations and comprehensive income.
Comprehensive Income (Loss)	'
	Comprehensive Income (Loss)
	The Company presents comprehensive income (loss) in two separate, but consecutive statements. In addition to Net income (loss), Comprehensive income (loss) includes foreign currency translation adjustments and actuarial gains and losses.
Earnings (Loss) per Share	'
	Earnings (Loss) per Share
	Basic earnings per share is computed by dividing the Company’s net income (loss) attributable to its stockholders, reduced by cumulative undeclared and paid dividends on preferred stock, by the weighted average number of shares of common stock outstanding during the period.
	Diluted earnings per share reflect the dilutive impact of potential common stock and unvested restricted shares of common stock in the weighted average number of common shares outstanding during the period, if dilutive. For this purpose, the “treasury stock method” and “if-converted method,” as applicable, are used. Under the treasury stock method, assumed proceeds upon the exercise of stock options are considered to be used to purchase common stock at the average market price of the shares during the period. Also under the treasury stock method, fixed awards and non-vested shares, such as restricted stock, are deemed options for purposes of computing diluted earnings per share. In applying the if-converted method, conversion is not assumed for purposes of computing diluted earnings per share if the effect would be antidilutive. Convertible preferred stock is antidilutive whenever the amount of the dividend declared in or accumulated for the current period per common share obtainable on conversion, including the deemed dividend in the period from a beneficial conversion feature, exceeds basic earnings per share. Also under the if-converted method, convertible debt is antidilutive whenever its interest per common share obtainable on conversion, including any deemed interest from a beneficial conversion feature and nondiscretionary adjustments, net of tax, exceeds basic earnings per share.
Research and Development	'
	Research and Development
	Research and development costs, which consist primarily of salaries, outside labor, material and equipment, are expensed as incurred.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standard Board ("FASB") issued ASU 2013-11, Income Taxes (Topic 740), Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force). Based on this update, an entity is required to present unrecognized tax benefits as a decrease in a net operating loss, similar tax loss or tax credit carryforward if certain criteria are met. The determination of whether a deferred tax asset is available is based on the unrecognized tax benefit and the deferred tax asset that exists at the reporting date and presumes disallowance of the tax position at the reporting date. This guidance will eliminate the diversity in practice in the presentation of unrecognized tax benefits but will not alter the way in which entities assess deferred tax assets for realizability. The amendments are effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2013. The amendments should be applied prospectively to unrecognized tax benefits that exist at the effective date. Early adoption is permitted. The adoption of this updated guidance is not expected to have any material impact on the Company's financial statements and related disclosures.
	In March 2013, the FASB issued ASU 2013-05, Foreign Currency Matters (Topic 830), Parent’s Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (a consensus of the FASB Emerging Issues Task Force). The amendments specify that a cumulative translation adjustment ("CTA") should be released into earnings when an entity ceases to have a controlling financial interest in a subsidiary or group of assets within a consolidated foreign entity and the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For sales of an equity method investment that is a foreign entity, a pro rata portion of CTA attributable to the investment would be recognized in earnings when the investment is sold. When an entity sells either a part or all of its investment in a consolidated foreign entity, CTA would be recognized in earnings only if the sale results in the parent no longer having a controlling financial interest in the foreign entity. In addition, CTA should be recognized in earnings in a business combination achieved in stages (i.e., a step acquisition). The amendments are effective for public companies for fiscal years, and interim periods within those years, beginning after December 15, 2013. The amendments should be applied prospectively to derecognition events occurring after the effective date. Early adoption is permitted. The adoption of this updated guidance is not expected to have any material impact on the Company's financial statements and related disclosures.
	In February 2013, the FASB issued ASU 2013-02, Comprehensive Income (Topic 220), Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This update requires companies to report, in one place, information about reclassifications out of accumulated other comprehensive income ("AOCI"). Companies also are required to present reclassifications by component when reporting changes in AOCI balances. For significant items reclassified out of AOCI to net income in their entirety in the period, companies must report the effect of the reclassifications on the respective line items in the statement where net income is presented. In certain circumstances, this can be done on the face of that statement. Otherwise, it must be presented in the notes. For items not reclassified to net income in their entirety in the period (e.g., pension amounts that are capitalized in inventory), companies must cross-reference in a note to other required disclosures. This update was effective for public companies in fiscal years, and interim periods within those years, beginning after December 15, 2012. The adoption of this updated guidance did not have any impact on the Company's financial statements and related disclosures.
	In July 2012, the FASB issued ASU 2012-02, Intangibles - Goodwill and Other (Topic 350), Testing Indefinite-Lived Intangible Assets for Impairment. In accordance with this update, an entity has the option first to assess qualitative factors to determine whether the existence of events and circumstances indicates that it is more likely than not that the indefinite-lived intangible asset is impaired. If, after assessing the totality of events and circumstances, an entity concludes that it is not more likely than not that the indefinite-lived intangible asset is impaired, then the entity is not required to take further action. However, if an entity concludes otherwise, then it is required to determine the fair value of the indefinite-lived intangible asset and perform the quantitative impairment test by comparing the fair value with the carrying amount and record an impairment charge, if any. This update was effective for annual and interim period impairment tests performed for fiscal years beginning after September 15, 2012. Early adoption was permitted. The adoption of this updated guidance did not have any impact on the Company's financial statements and related disclosures.

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Schedule of segment information	'
	Year ended December 31, 2012	Resources		Chemicals and Oxides			Magnetic Materials and Alloys			Rare Metals (d)		Corporate and other(a)		Eliminations(b)		Total Molycorp, Inc.
	Revenues:	(In thousands of dollars)
	External	88,870		181,849			179,335			77,642				—		527,696
	Intersegment	7,256		25,717										(32,973	)	—
	Total revenues	96,126		207,566			179,335			77,642				(32,973	)	527,696
	Depreciation, amortization and accretion	(13,991	)	(13,110	)		(19,737	)		(5,837	)	(133	)	—		(52,808	)
	Operating loss (e)	(70,220	)	(191,059	)		(125,543	)		(18,671	)	(85,459	)	24,803		(466,149	)
	Loss before income taxes and equity earnings	(70,469	)	(190,094	)		(126,981	)		(18,181	)	(143,269	)	24,803		(524,191	)
	Total assets at December 31, 2012	1,802,842		639,847			593,197			117,961		575,964		(737,276	)	2,992,535
	Capital expenditures (c)	814,054		10,910			5,614			10,750		1,733		—		843,061
	Year ended December 31, 2011	Resources		Chemicals and Oxides			Magnetic Materials and Alloys			Rare Metals		Corporate and other(a)		Eliminations(b)		Total Molycorp, Inc.
	Revenues:	(In thousands of dollars)
	External	253,563		40,216			56,772			46,280				—		396,831
	Intersegment	55,155		13,902			—			—				(69,057	)	—
	Total revenues	308,718		54,118			56,772			46,280				(69,057	)	396,831
	Depreciation, amortization and accretion	(10,553	)	(1,958	)		(236	)		(2,449	)	(31	)	—		(15,227	)
	Operating income (loss)	218,549		8,700			2,331			2,131		(51,402	)	(27,443	)	152,866
	Income (loss) before income taxes	218,391		5,785			2,336			(634	)	(51,525	)	(27,443	)	146,910
	Total assets at December 31, 2011	824,712		46,368			30,061			71,634		426,080		(143,730	)	1,255,125
	Capital expenditures (c)	401,047		8,170			—			—		—		—		409,217
	(a)	Corporate and other loss before income taxes and equity earnings includes business development costs, personnel costs, stock-based compensation, accounting and legal fees, occupancy expense, information technology costs and interest expense. Total Corporate and other assets is comprised primarily of cash and cash equivalents.
	(b)	The net elimination in operating results includes costs of sales eliminations of $62,343, $57,776 and $41,614 for the years ended December 31, 2013, 2012 and 2011, respectively, which consist of intercompany gross profits as well as eliminations of lower of cost or market adjustments related to intercompany inventory. The total assets elimination is comprised primarily of intercompany investments and intercompany accounts receivable and profits in inventory.
	(c)	On an accrual basis excluding capitalized interest.
	(d)	Excludes operating results from the Napanee facility, which is treated as a discontinued operation for comparative purposes.
	(e)	Includes impairment of goodwill and other long-lived assets in some segments. See notes 7 and 9 below for details.
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	'
	The geographic distribution of the Company’s revenues based on customers' locations for the years ended December 31, 2013, 2012 and 2011, was as follows:
		Years Ended December 31,
		2013			2012				2011
		(In thousands)
	Asia:
	China	$	199,021		$	118,086			$	421
	Japan	99,952			160,942				204,262
	Thailand	17,129			7,674				—
	Hong Kong	8,815			4,793				—
	South Korea	12,418			3,828				—
	Singapore	54			212				—
	North America	92,066			103,555				128,544
	Europe	113,549			117,907				56,760
	Other	11,386			10,699				6,844
	Total	$	554,390		$	527,696			$	396,831
	Long-lived tangible assets by geographic location at December 31, 2013 and 2012 were as follows:
		At December 31,
		2013			2012
		(In thousands)
	North America	$	1,627,892		$	1,391,690
	Europe	73,674			75,495
	China	53,131			52,914
	Thailand	6,213			5,902
	Other Asia	1,913			18,221
	Other	51			82
	Total	$	1,762,874		$	1,544,304

Inventory_Tables

Inventory (Tables)	12 Months Ended
	Dec. 31, 2013
Inventory Disclosure [Abstract]	'
Schedule of inventory	'
	At December 31, 2013 and 2012, inventory consisted of the following:
		December 31,
		2013		2012
		(In thousands)
	Current:
	Concentrate stockpiles	$	24	$	6,393
	Raw materials	42,627		95,248
	Work in process	41,962		55,229
	Finished goods	65,662		114,903
	Materials and supplies	21,508		15,603
	Total current	$	171,783	$	287,376
	Long-term:
	Concentrate stockpiles	$	4	$	4
	Raw materials	25,325		26,092
	Total long-term	$	25,329	$	26,096

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2013
Deposits [Abstract]	'
Schedules of Deposits	'
	The Company had $26.0 million and $26.8 million in deposits reported as non-current assets at December 31, 2013 and 2012, respectively, which consisted of the following:
		December 31,
		2013		2012
		(In thousands)
	Escrow arrangement with Kern River Gas Transmission Company ("Kern River")	$	20,612	$	20,612
	Construction insurance program	1,504		1,504
	Collateral placed against the surety bonds issued to California state and regional agencies for the closure and reclamation obligations at the Molycorp Mountain Pass facility, and other deposits	3,881		4,653
	Total	$	25,997	$	26,769

Property_Plant_and_Equipment_n1

Property, Plant and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Schedule of property, plant and equipment	'
	At December 31, 2013 and 2012, property, plant and equipment consisted of the following:
		December 31,
		2013			2012
		(In thousands)
	Land	$	12,822		$	12,475
	Land improvements (15 to 30 years)	327,029			63,269
	Buildings and improvements (4 to 40 years)	418,510			237,379
	Plant and equipment (2 to 15 years)	288,603			194,934
	Vehicles (7 years)	2,986			2,842
	Computer software (5 years)	12,424			9,528
	Furniture and fixtures (5 years)	1,044			1,116
	Construction in progress (a)	755,107			1,011,541
	Natural gas delivery facility under capital lease (10 years)	15,658			15,658
	Mining equipment under capital lease (7 years)	7,370			—
	Mineral properties (Note 8)	23,999			24,327
	Exploration rights (Note 8)	—			16,166
	Property, plant and equipment at cost	1,865,552			1,589,235
	Less accumulated depreciation	(102,678		)	(44,931		)
	Property, plant and equipment, net	$	1,762,874		$	1,544,304
	(a)	Primarily related to expenditures at the Molycorp Mountain Pass facility

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Goodwill	'
	Changes in the carrying value of goodwill by reportable segment during the years ended December 31, 2013, 2012 and 2011, were as follows:
		Chemicals and Oxides				Magnetic Materials and Alloys				Rare Metals				Total
		(In thousands)
	31-Dec-10	$	—			$	—			$	—			$	—
	Goodwill acquired	728				1,977				727				3,432
	31-Dec-11	728				1,977				727				3,432
	Goodwill acquired	285,633				213,525				27,046				526,204
	Impairment	(161,132		)		(112,694		)		(16,068		)		(289,894		)
	31-Dec-12	125,229				102,808				11,705				239,742
	Impairment	—				—				(10,992		)		(10,992		)
	31-Dec-13	$	125,229			$	102,808			$	713			$	228,750
Schedule of amortizable intangible assets	'
	Intangible Assets
	At December 31, 2013 and 2012, intangible assets consisted of the following:
		Customer relationships			Rare earths quotas			Patents			Trade names			Land use rights			Other		Total
	Gross carrying amount	(In thousands)
	31-Dec-12	$	344,774		$	78,300		$	33,252		$	15,586		$	3,568		$	4,420	$	479,900
	Additions	48			—			—			—			—			—		48
	Foreign currency translation adjustment	(242		)	—			—			—			—			—		(242		)
	Impairment	—			(78,300		)	(33,100		)	—			—			—		(111,400		)
	31-Dec-13	$	344,580		$	—		$	152		$	15,586		$	3,568		$	4,420	$	368,306
	Accumulated Amortization
	31-Dec-12	$	14,095		$	4,035		$	9,365		$	1,152		$	66		$	249	$	28,962
	Amortization	22,145			7,018			13,554			65			161			613		43,556
	Adjustments	(260		)	—			—			(874		)	—			—		(1,134		)
	Impairment	—			(11,053		)	(22,892		)	—			—			—		(33,945		)
	31-Dec-13	35,980			—			27			343			227			862		37,439
	Net book value	$	308,600		$	—		$	125		$	15,243		$	3,341		$	3,558	$	330,867
		Customer relationships			Rare earths quotas			Patents			Trade names			Land use rights			Other		Total
	Gross carrying amount	(In thousands)
	31-Dec-11	$	2,669		$	—		$	—		$	786		$	—		$	—	$	3,455
	Additions	342,105			78,300			39,252			14,800			3,568			4,420		482,445
	Impairment	—			—			(6,000		)	—			—			—		(6,000		)
	31-Dec-12	$	344,774		$	78,300		$	33,252		$	15,586		$	3,568		$	4,420	$	479,900
	Accumulated Amortization
	31-Dec-11	$	170		$	—		$	—		$	213		$	—		$	—	$	383
	Amortization	13,925			4,035			9,365			939			66			249		28,579
	31-Dec-12	14,095			4,035			9,365			1,152			66			249		28,962
	Net book value	$	330,679		$	74,265		$	23,887		$	14,434		$	3,502		$	4,171	$	450,938
Schedule of Expected Amortization Expense	'
	Amortization expense for the next five years and thereafter is expected to be as follows:
		(In thousands)
	2014	$	23,816
	2015	23,789
	2016	23,740
	2017	23,740
	2018	23,576
	Thereafter	197,406

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Equity Method Investments	'
	The following table provides a reconciliation of the carrying value of the Company's investments at December 31, 2013 and 2012:
		Investment at cost			Equity Method Investments
		Boulder Wind Power, Inc.			IMJ			Keli			Ingal Stade			Other investments at cost				Total
		(In thousands)
	31-Dec-11	$	20,000		$	—		$	—		$	—		$	—			$	20,000
	Additions	—			27,598			12,200			4,900			2,828				47,526
	Equity loss	n/a			(2,405		)	(1,200		)	115			n/a				(3,490		)
	31-Dec-12	20,000			25,193			11,000			5,015			2,828				64,036
	Additions	—			3,419			—			—			—				3,419
	Equity loss	n/a			(6,529		)	(2,600		)	(40		)	n/a				(9,169		)
	Impairment	(8,000		)	—			—			—			(1,411		)	(a)	(9,411		)
	31-Dec-13	$	12,000		$	22,083		$	8,400		$	4,975		$	1,417			$	48,875
	(a) The impairment charge in 2013 relates to the equity interest in Atlantic Metals & Alloys, LLC.
Schedule of Cost Method Investments	'
	The following table provides a reconciliation of the carrying value of the Company's investments at December 31, 2013 and 2012:
		Investment at cost			Equity Method Investments
		Boulder Wind Power, Inc.			IMJ			Keli			Ingal Stade			Other investments at cost				Total
		(In thousands)
	31-Dec-11	$	20,000		$	—		$	—		$	—		$	—			$	20,000
	Additions	—			27,598			12,200			4,900			2,828				47,526
	Equity loss	n/a			(2,405		)	(1,200		)	115			n/a				(3,490		)
	31-Dec-12	20,000			25,193			11,000			5,015			2,828				64,036
	Additions	—			3,419			—			—			—				3,419
	Equity loss	n/a			(6,529		)	(2,600		)	(40		)	n/a				(9,169		)
	Impairment	(8,000		)	—			—			—			(1,411		)	(a)	(9,411		)
	31-Dec-13	$	12,000		$	22,083		$	8,400		$	4,975		$	1,417			$	48,875
	(a) The impairment charge in 2013 relates to the equity interest in Atlantic Metals & Alloys, LLC.

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2013
Business Acquisition [Line Items]	'
Schedule of Business Acquisitions, Transaction Costs by Type	'
	For the year ended December 31, 2012, the Company recognized approximately $62.0 million of transaction costs related to the Molycorp Canada acquisition in the consolidated statement of operations and comprehensive income as follows:
		(In thousands)
	Corporate development
	Legal, accounting and advisory fees	$	16,498
	Other expenses:
	Contingent forward contract loss	$	37,589
	Interest expense:
	Bridge loan fee	$	7,937
Molycorp Canada	'
Business Acquisition [Line Items]	'
Summarizes the purchase prices and opening balance sheets for the acquisitions	'
		Preliminary Allocation of Consideration Transferred as of December 31, 2012			Measurement Period Adjustments			Final Allocation of Consideration Transferred
	Purchase consideration:	(In thousands)
	Cash consideration	$	908,181					$	908,181
	Fair value of Molycorp common stock and Exchangeable Shares issued	284,144						284,144
	Total purchase consideration	$	1,192,325					$	1,192,325
	Estimated fair values of the assets and liabilities acquired:
	Cash and cash equivalents	$	317,169		$	—		$	317,169
	Restricted cash	4,951			—			4,951
	Accounts receivable	101,470			—			101,470
	Inventory	250,989			—			250,989
	Prepaid expenses and other current assets	26,893			—			26,893
	Property, plant and equipment	75,745			—			75,745
	Investments	21,019			(1,091		)	19,928
	Intangibles	482,234			—			482,234
	Deferred tax charges	13,435			—			13,435
	Deferred tax assets	11,473			(1,423		)	10,050
	Goodwill	494,809			31,616			526,425
	Other non-current assets	4,367			—			4,367
	Accounts payable and accrued expenses	(138,576		)	—			(138,576		)
	Debt	(255,338		)	—			(255,338		)
	Other current liabilities	(33,990		)	—			(33,990		)
	Deferred tax liabilities	(154,309		)	5,880			(148,429		)
	Other non-current liabilities	(14,255		)	—			(14,255		)
	Non-controlling interests	(15,761		)	(34,982		)	(50,743		)
	Total purchase consideration	$	1,192,325		$	—		$	1,192,325
Summary of actual and pro forma information	'
	(In thousands, except per share amounts)	Revenues				Net income (loss)				Net income (loss)			EPS Basic
										attributable to Molycorp
	Unaudited pro forma January 1, 2012 to December 31, 2012 (combined entity)	$	863,728			$	(463,716	)		$	(473,249	)	$	(4.53	)
	Unaudited pro forma January 1, 2011 to December 31, 2011 (combined entity)	$	1,196,876			$	241,903			$	231,772		$	2.66
Molycorp Silmet and MMA	'
Business Acquisition [Line Items]	'
Summarizes the purchase prices and opening balance sheets for the acquisitions	'
	The following table summarizes purchase consideration as well as the estimated fair value of the assets acquired and liabilities assumed for the acquisition of 90.023% controlling interest in Molycorp Silmet on April 1, 2011 and of MMA on April 15, 2011 (in thousands):
	(In thousands)	Molycorp Silmet				MMA
		April 1, 2011				April 15, 2011
	Purchase consideration:
	Cash consideration	$	9,021			$	17,500
	Fair value of Molycorp common stock issued	72,653				—
	Total purchase consideration	$	81,674			$	17,500
	Fair values of the assets and liabilities acquired:
	Cash	$	105			$	6,395
	Accounts receivable and other current assets	8,626				5,474
	Inventory	37,404				11,327
	Property, plant and equipment, net	63,393				4,512
	Intangible assets subject to amortization	2,669				—
	Goodwill	1,455				1,977
	Liabilities	(19,974		)		(8,989		)
	Deferred tax liabilities	—				(3,196		)
	Long-term debt	(3,184		)		—
	Noncontrolling interest	(8,820		)		—
	Total purchase consideration	$	81,674			$	17,500
Summary of actual and pro forma information	'
	:
	(In thousands, except per share amounts)	Revenues				Net income				Net income			EPS Basic
										attributable to
										Molycorp
	Unaudited pro forma January 1, 2011 to December 31, 2011 (combined entity)	$	430,305			$	105,397			$	104,590		$	1.13

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2013
Payables and Accruals [Abstract]	'
Schedule of accrued expenses	'
	Accrued expenses at December 31, 2013 and 2012 consisted of the following:
		December 31,
		2013		2012
		(In thousands)
	Defined contribution plan	$	1,921	$	1,400
	Professional fees	135		4,971
	Accrued payroll and related benefits	5,739		7,532
	Sales and use tax	3,354		7,187
	Bonus accrual	4,449		3,503
	Interest payable	18,158		15,253
	Advance from customer	600		1,753
	Withholding taxes	2,563		2,929
	Amount payable to noncontrolling interest	352		9,640
	Other accrued expenses	11,230		4,845
	Total accrued expenses	$	48,501	$	59,013

Asset_Retirement_Obligation_Ta

Asset Retirement Obligation (Tables)	12 Months Ended
	Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of activity in asset retirement obligation	'
	The following table presents the activity in the Company’s asset retirement obligation ("ARO") for the years ended December 31, 2013 and 2012:
		December 31,
		2013			2012
		(In thousands)
	Balance at beginning of period	$	22,125		$	15,541
	Obligations settled	(3,849		)	(2,954		)
	Accretion expense	1,328			1,299
	Revisions in estimated cash flows	(3,793		)	7,872
	Loss on settlement	1,772			367
	Balance at end of period	$	17,583		$	22,125

Debt_and_Capital_Lease_Obligat1

Debt and Capital Lease Obligations (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Summary of the current and non-current portions of the debt outstanding	'
	The following tables provide a summary of the current and non-current portions of the debt outstanding at December 31, 2013 and 2012:
		December 31,
		2013							2012
		Current				Non-Current			Current				Non-Current
		(In thousands)
	Bank loans due May 2014 - September 2017	$	14,128			$	2,699		$	39,252			$	4,118
	3.25% Convertible Notes, net of discount, due June 2016	—				207,028			—				198,689
	6.00% Convertible Notes, net of discount, due September 2017	—				346,708			—				331,977
	5.00% Debentures, net of discount, due December 2017	—				2,493			—				2,774
	5.50% Convertible Notes, net of discount, due February 2018	—				148,198			—				—
	10% Senior Secured Notes, net of discount, due June 2020	—				637,435			—				636,111
	Total debt	14,128				1,344,561			39,252				1,173,669
	Capital lease obligations	2,234				19,355			352				15,163
	Total debt and capital lease obligations	$	16,362			$	1,363,916		$	39,604			$	1,188,832
Schedule of Long-term Debt Conversions	'
		3.25% Convertible Notes						6.00% Convertible Notes							5.50% Convertible Notes				10% Senior Notes
		At December 31,
		2013			2012			2013			2012				2013			2012	2013			2012
		(In thousands)
	Principal amount	$	230,000		$	230,000		$	414,000		$	414,000			$	172,500		n/a	$	650,000		$	650,000
	Unamortized debt discount	(22,972		)	(31,311		)	(67,292		)	(82,023		)		(24,302		)	n/a	(12,565		)	(13,889		)
	Net carrying amount	$	207,028		$	198,689		$	346,708		$	331,977			$	148,198		n/a	$	637,435		$	636,111
	Interest cost (a)	$	15,839		$	15,312		$	39,779		$	17,457			$	13,107		n/a	$	66,323		$	40,070
	(a) Interest cost includes the coupon interest, accretion of the initial equity component of the convertible notes described below (3.25% - $36,227; 6.00% - $68,695; and 5.50% - $21,815), accretion of the underwriting discounts and amortization of the issuance costs allocated to the liability component.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Schedule of Components of Income Tax Expense	'
	Income tax expense consisted of the following for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	Current
	Federal	$	(2,581	)	$	(22,418	)	$	18,721
	Foreign	(1,018		)	8,994			—
	State	792			(4,197		)	6,952
	Total current	(2,807		)	(17,621		)	25,673
	Deferred
	Federal	(43,479		)	(20,786		)	3,687
	Foreign	(16,517		)	(11,777		)	—
	State	(8,140		)	(3,891		)	(784		)
	Total deferred	(68,136		)	(36,454		)	2,903
	Total tax provision	$	(70,943	)	$	(54,075	)	$	28,576
Schedule of Income before Income Tax, Domestic and Foreign	'
	The components of earnings before income taxes, by tax jurisdiction, were as follows for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	United States	$	(286,818	)	$	(161,129	)	$	141,801
	Foreign	(145,458		)	(363,062		)	5,109
	Total	$	(432,276	)	$	(524,191	)	$	146,910
Schedule of Effective Income Tax Rate Reconciliation	'
	A reconciliation of the statutory federal income tax rate of 35% to the Company's effective income tax rate is as follows for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	Federal tax computed at the statutory rate	$	(151,297	)	$	(184,075	)	$	51,419
	State taxes, net of federal benefit	(10,329		)	(5,970		)	5,255
	Change in valuation allowance	85,881			19,515			(22,730		)
	Impairment of goodwill and other long-lived assets	7,458			103,563			—
	Acquisition costs	—			4,945			—
	Changes related to uncertain tax positions	(5,153		)	(14,176		)	—
	Federal and State tax credits	2,946			(6,817		)	(2,627		)
	Domestic production activities deduction	—			2,493			(2,493		)
	Foreign income tax rate differential	24,315			18,682			(1,735		)
	Foreign translation adjustments	(7,744		)	—			—
	Change in applicable law	(5,884		)	—			—
	Other items, net	(11,136		)	7,765			1,487
	Income tax expense	$	(70,943	)	$	(54,075	)	$	28,576
Schedule of Deferred Tax Assets and Liabilities	'
	The tax effect of temporary differences and net operating losses, which give rise to deferred tax assets and liabilities, consisted of the following at December 31, 2013 and 2012:
		At December 31,
		2013			2012
		(In thousands)
	Deferred tax assets:
	Current:
	Inventory	$	2,570		$	11,951
	Other	2,605			2,468
	Total current	5,175			14,419
	Non-current:
	Asset retirement obligation	—			165
	Mineral resources	16,886			16,780
	Property, plant and equipment and intangible assets	21,044			13,435
	Stock compensation	1,964			1,724
	Net operating losses	144,366			56,156
	Research and energy tax credits	6,233			10,473
	Alternative Minimum Tax Credit	2,216			1,611
	Unrealized foreign exchange	5,664			—
	Investments	3,120			—
	Other	4,107			823
	Total non-current	205,600			101,167
	Deferred tax liabilities:
	Current
	Inventory	1,312			3,395
	Other	1,423			541
	Total current	2,735			3,936
	Non-current:
	Asset retirement obligation	1,190			—
	Foreign subsidiary earnings and withholding taxes	14,804			32,637
	Property, plant and equipment and intangible assets	91,585			137,010
	Section 174 costs	33,942			24,814
	Convertible debt (Notes)	44,275			40,478
	Other	302			6,966
	Total non-current	186,098			241,905
	Net deferred taxes, before valuation allowance	21,942			(130,255		)
	Valuation allowance	(107,358		)	(20,631		)
	Total deferred tax	$	(85,416	)	$	(150,886	)
Schedule of Income Tax Contingencies	'
	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	Balance, beginning of year	$	6,219		$	519		$	—
	Tax position related to current year:
	Additions	—			4,737			519
	Tax positions related to prior years:
	Additions	—			16,109			—
	Settlements	(4,737		)	(13,740		)	—
	Statute of limitations closures	(416		)	(1,406		)	—
	Balance, end of year	$	1,066		$	6,219		$	519

Earnings_per_Share_Tables

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Schedule of earnings per share, basic and diluted	'
	1

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	'
	:
		2013		2012		2011
		(In millions)
	Stock-based compensation expense	$5.40		$3.40		$4.70
	Income tax benefit	$—		$0.90		$0.80
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	'
	The significant assumptions used to estimate the fair value of the stock options granted in 2011 were as follows:
	Risk-free interest rate	2.21%
	Expected term (in years)	6
	Volatility	60.10%
	Expected dividend yield	0
Summary of the Activity and Other Information Related to Stock Option Awards	'
	The following table summarizes the activity related to stock options in 2013:
	Stock Options	Number of			Weighted Average
		Shares			Exercise Price
	Outstanding at January 1, 2013	35,624			$48.87
	Granted	—			—
	Exercised	—			—
	Forfeited and expired	(9,008	)		48.87
	Outstanding at December 31, 2013	26,616			$48.87
	Options exercisable at December 31, 2013	17,744			$48.87
	Additional annual information for stock options is included in the following table:
		2013		2012		2011
		(In millions)
	Weighted average grant-date fair value of options granted	n/a		n/a		$1.50
	Total intrinsic value of options exercised	n/a		n/a		n/a
	Total fair value of options vested	$0.50		$0.30		n/a
PBRSUs	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Summary of Activity Related to Stock-based Awards	'
	The following tables summarize the activity related to restricted stock-based awards for the year ended December 31, 2013:
	PBRSUs	Number of			Weighted Average
		Shares			Grant-Date
					Price
	Unvested at January 1, 2013	29,302			$30.33
	Granted	897,515			$6.84
	Forfeited	(69,546	)		$11.00
	Vested	(159,474	)		6.64
	Unvested at December 31, 2013	697,797			$7.45
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	Additional annual information for restricted stock-based awards is included in the following tables:
	PBRSUs	2013		2012		2011
		(In millions)
	Weighted average grant-date fair value of shares granted	$6.10		$1.40		n/a
	Total fair value of shares vested	$1.10		n/a		n/a
RSUs	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Summary of Activity Related to Stock-based Awards	'
	RSUs	Number of			Weighted Average
		Shares			Grant-Date
					Price
	Unvested at January 1, 2013	181,602			$32.15
	Granted	1,005,757			$7.02
	Forfeited	(85,119	)		$27.15
	Vested*	(25,855	)		$6.89
	Unvested at December 31, 2013	1,076,385			$9.81
	*	Includes: a) deferral and conversion of a portion of fees payable to certain non-employee directors of the Company; b) deferral and conversion of a portion of the 2012 annual cash bonuses paid to certain executive officers and other employees of the Company; and c) RSUs with an accelerated vesting period that were granted to some employees of Molycorp Canada on the acquisition date.
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	RSUs	2013		2012		2011
	Weighted average grant-date fair value of shares granted	$7.10		$5.50		$4.50
	Total intrinsic value of share units converted	$0.20		$0.40		$0.10
	Total fair value of shares vested	$0.20		$0.80		$0.10
Restricted Stock	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Summary of Activity Related to Stock-based Awards	'
	RSAs	Number of			Weighted Average
		Shares			Grant-Date
					Price
	Unvested at January 1, 2013	39,974			$40.09
	Granted	—			—
	Forfeited	(8,148	)		$39.77
	Vested	(25,500	)		$36.51
	Unvested at December 31, 2013	6,326			$55.05
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	RSAs	2013		2012		2011
	Weighted average grant-date fair value of shares granted	n/a		n/a		$0.60
	Total fair value of shares vested	$0.90		n/a		n/a

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of future minimum rental payments for operating leases	'
	The Company leased certain office space, trailers and equipment pursuant to lease agreements that have been determined to be operating lease. Remaining annual minimum payments under these leases at December 31, 2013 were as follows:
	(In thousands)	Total		Less Than		1 - 3 Years		4 - 5 Years		More Than
				1 Year						5 Years
	Operating lease obligations	$	6,283	$	2,583	$	2,263	$	442	$	995
Schedule of minimum payments for purchase obligations	'
	Future payments for all purchase commitments at December 31, 2013 were as follows:
	(In thousands)	Total		Less Than		1 - 3 Years		4 - 5 Years		More Than
				1 Year						5 Years
	Purchase obligations and other commitment	$	238,945	$	216,249	$	12,813	$	6,239	$	3,644

Net_Change_in_Operating_Assets1

Net Change in Operating Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Net Change in Operating Assets and Liabilities	'
Schedule of changes in operating assets and liabilities, net of the effects of acquisitions and dispositions	'
	Net change in operating assets and liabilities, net of the effects of acquisitions and dispositions, consisted of the following:
		Years Ended December 31,
		2013			2012			2011
		(In thousands)
	Decrease (increase) in operating assets:
	Accounts receivable	$	(8,986	)	$	124,983		$	(52,805	)
	Inventory	15,649			(46,126		)	(64,543		)
	Prepaid expenses and other assets	(5,728		)	33,520			(6,363		)
	Increase (decrease) in operating liabilities:
	Accounts payable	(24,177		)	(34,972		)	16,233
	Income tax payable	18,966			(40,263		)	(17,832		)
	Interest payable	(39,120		)	(40,792		)	—
	Asset retirement obligation	(7,642		)	(1,467		)	(1,030		)
	Accrued expenses	(13,681		)	(54,763		)	6,151
		$	(64,719	)	$	(59,880	)	$	(120,189	)

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2013
Supplemental Cash Flow Information [Abstract]	'
Summary of Supplemental Cash Flow Information	'
		Years Ended December 31,
		2013		2012	2011
		(In thousands of dollars)
	Net cash paid for:
	Income taxes	(13,429	)	178	43,505
	Interest, net of capitalized interest	32,833		8,942	273
	Non-cash financing activities and investing activities:
	Change in accrued capital expenditures	58,673		52,189	112,606
	Conversion of debt securities to equity securities	18		4,527	—
	Acquisition of exploration rights	—		8,000	—
	Debt assumed from business acquisitions	—		40,691	3,184
	Issuance of common stock for business acquisitions	—		284,100	72,700
	Fixed assets additions under capital lease	7,370		15,658	—

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Inputs, Liabilities, Quantitative Information	'
	The technique used by the Company to fair value this derivative is the income approach based on a discounted cash flow model. In addition to the risk free interest rate, which is a Level 1 input within the fair value hierarchy, the following significant unobservable Level 3 inputs were used to fair value the put option as of December 31, 2013:
				Effect of 1% increase (a)			Effect of 1% decrease (a)
		Input		(In millions)
	Equity-risk premium	6.5	%	$	(0.6	)	$	0.7
	Risk premium	12.9	%	$	(0.2	)	$	0.3
	Size premium	3.8	%	$	(0.3	)	$	0.4
	Growth rate	1	%	$	0.2		$	(0.2	)
	(a) Assuming all other inputs are unchanged.

Subsidiary_Guarantor_Financial1

Subsidiary Guarantor Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Schedule of Condensed Balance Sheet	'
		At December 31, 2012
		(In thousands)
	Condensed Consolidating Balance Sheets	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
	Current assets:
	Cash and cash equivalents	$	16,560		$	18,020		$	193,210		$	—		$	227,790
	Trade accounts receivable, net	—			7,738			44,692			—			52,430
	Inventory	—			49,416			237,960			—			287,376
	Deferred charges	—			2,203			7,209			—			9,412
	Deferred tax assets	—			—			11,731			(1,942		)	9,789
	Income tax receivable	—			25,087			—			—			25,087
	Prepaid expenses and other current assets	—			9,085			12,709			—			21,794
	Total current assets	16,560			111,549			507,511			(1,942		)	633,678
	Non-current assets:
	Deposits	1,752			24,862			155			—			26,769
	Property, plant and equipment, net	—			1,377,147			167,157			—			1,544,304
	Inventory	—			26,096			—			—			26,096
	Intangible assets, net	—			508			450,430			—			450,938
	Investments	—			45,241			18,795						64,036
	Deferred tax assets	6,030			—			—			(6,030		)	—
	Goodwill	—			—			239,742			—			239,742
	Investments in consolidated subsidiaries	883,319			97,960			—			(981,279		)	—
	Intercompany accounts receivable	1,539,877			207,035			794			(1,747,706		)	—
	Other non-current assets	—			885			6,087			—			6,972
	Total non-current assets	2,430,978			1,779,734			883,160			(2,735,015		)	2,358,857
	Total assets	$	2,447,538		$	1,891,283		$	1,390,671		$	(2,736,957	)	$	2,992,535
	Current liabilities:
	Trade accounts payable	$	—		$	191,769		$	50,225		$	—		$	241,994
	Accrued expenses	14,872			10,087			34,054			—			59,013
	Income tax payable	—			—			15,267			—			15,267
	Deferred tax liabilities	—			1,942			—			(1,942		)	—
	Debt and capital lease obligations	—			352			39,252			—			39,604
	Other current liabilities	—			3,539			—			—			3,539
	Total current liabilities	14,872			207,689			138,798			(1,942		)	359,417
	Non-current liabilities:
	Asset retirement obligation	—			18,586			—			—			18,586
	Deferred tax liabilities	—			23,130			143,575			(6,030		)	160,675
	Debt and capital lease obligations	1,166,777			15,163			6,892			—			1,188,832
	Derivative liability	—			—			7,816			—			7,816
	Pension liabilities	—			—			3,292			—			3,292
	Intercompany accounts payable	49,843			1,577,363			120,500			(1,747,706		)	—
	Other non-current liabilities	—			1,102			1,557			—			2,659
	Total non-current liabilities	1,216,620			1,635,344			283,632			(1,753,736		)	1,381,860
	Total liabilities	$	1,231,492		$	1,843,033		$	422,430		$	(1,755,678	)	$	1,741,277
	Stockholders’ equity:
	Common stock	139			—			—			—			139
	Preferred stock	2			—			—			—			2
	Additional paid-in capital	1,691,429			149,857			1,283,863			(1,433,720		)	1,691,429
	Accumulated other comprehensive loss	(9,433		)	—			(9,433		)	9,433			(9,433		)
	Accumulated deficit	(466,091		)	(101,607		)	(341,401		)	443,008			(466,091		)
	Total Molycorp stockholders’ equity	1,216,046			48,250			933,029			(981,279		)	1,216,046
	Noncontrolling interests	—			—			35,212			—			35,212
	Total stockholders’ equity	1,216,046			48,250			968,241			(981,279		)	1,251,258
	Total liabilities and stockholders’ equity	$	2,447,538		$	1,891,283		$	1,390,671		$	(2,736,957	)	$	2,992,535
Schedule of Condensed Income Statement and Comprehensive Income	'
		Year Ended December 31, 2012
		(In thousands)
	Condensed Consolidating Statements of Operations and Comprehensive Income	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
	Revenues	$	—		$	139,257		$	413,951		$	(25,512	)	$	527,696
	Costs of sales:
	Costs excluding depreciation and amortization	—			(153,461		)	(350,304		)	25,512			(478,253		)
	Depreciation and amortization	—			(12,094		)	(18,527		)	—			(30,621		)
	Gross (loss) profit	—			(26,298		)	45,120			—			18,822
	Operating expenses:
	Selling, general and administrative	46			(86,493		)	(26,990		)	—			(113,437		)
	Corporate development	(46		)	(19,750		)	—			—			(19,796		)
	Depreciation, amortization and accretion	—			(2,220		)	(19,967		)	—			(22,187		)
	Research and development	—			(12,984		)	(14,812		)	—			(27,796		)
	Impairment of goodwill and other long-lived assets	—			(5,747		)	(296,008		)	—			(301,755		)
	Operating loss	—			(153,492		)	(312,657		)	—			(466,149		)
	Other (expense) income:
	Other expense	(37,589		)	(328		)	(881		)	—			(38,798		)
	Foreign exchange gains, net	—			—			2,872			—			2,872
	Interest expense, net	(18,118		)	(3,496		)	(502		)	—			(22,116		)
	Interest income (expense) from intercompany notes	25,157			3,152			(28,309		)	—			—
	Equity earnings from consolidated subsidiaries	(456,649		)	(23,205		)	—			479,854			—
		(487,199		)	(23,877		)	(26,820		)	479,854			(58,042		)
	Loss from continuing operations before income taxes and equity earnings	(487,199		)	(177,369		)	(339,477		)	479,854			(524,191		)
	Income tax benefit (expense)	6,030			53,840			(5,795		)	—			54,075
	Equity in results of affiliates	—			(2,439		)	(1,051		)	—			(3,490		)
	Loss from continuing operations	(481,169		)	(125,968		)	(346,323		)	479,854			(473,606		)
	Loss from discontinued operations, net of tax	—			—			(1,737		)	—			(1,737		)
	Net loss	(481,169		)	(125,968		)	(348,060		)	479,854			(475,343		)
	Net income attributable to noncontrolling interest	—			—			(5,826		)	—			(5,826		)
	Net loss attributable to Molycorp stockholders	$	(481,169	)	$	(125,968	)	$	(353,886	)	$	479,854		$	(481,169	)
	Net loss	$	(481,169	)	$	(125,968	)	$	(348,060	)	$	479,854		$	(475,343	)
	Other comprehensive income:
	Foreign currency translation adjustments	—			—			248			—			248
	Actuarial gain (loss)	—			—			(1,200		)	—			(1,200		)
	Comprehensive loss	$	(481,169	)	$	(125,968	)	$	(349,012	)	$	479,854		$	(476,295	)
	Comprehensive loss attributable to:
	Molycorp stockholders	(481,169		)	(125,968		)	(343,186		)	479,854			(470,469		)
	Noncontrolling interest	—			—			(5,826		)	—			(5,826		)
		$	(481,169	)	$	(125,968	)	$	(349,012	)	$	479,854		$	(476,295	)
		Year Ended December 31, 2011
		(In thousands)
	Condensed Consolidating Statements of Operations and Comprehensive Income	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
	Revenues	$	—		$	365,490		$	100,398		$	(69,057	)	$	396,831
	Costs of sales:
	Costs excluding depreciation and amortization	—			(158,951		)	(74,457		)	69,057			(164,351		)
	Depreciation and amortization	—			(9,411		)	(4,128		)	—			(13,539		)
	Gross profit	—			197,128			21,813			—			218,941
	Operating expenses:
	Selling, general and administrative	(7		)	(48,296		)	(2,454		)	—			(50,757		)
	Corporate development	—			(5,912		)	—			—			(5,912		)
	Depreciation, amortization and accretion	—			(1,378		)	(310		)	—			(1,688		)
	Research and development	—			(7,718		)	—			—			(7,718		)
	Operating (loss) income	(7		)	133,824			19,049			—			152,866
	Other (expense) income:
	Other expense	—			(153		)	—			—			(153		)
	Foreign exchange losses, net	—			—			(5,415		)	—			(5,415		)
	Interest (expense) income, net	(499		)	248			(137		)	—			(388		)
	Interest income (expense) from intercompany notes	424			(296		)	(128		)	—			—
	Equity earnings from consolidated subsidiaries	117,608			12,485			—			(130,093		)	—
		117,533			12,284			(5,680		)	(130,093		)	(5,956		)
	Income before income taxes	117,526			146,108			13,369			(130,093		)	146,910
	Income tax expense	—			(28,500		)	(76		)	—			(28,576		)
	Net income	117,526			117,608			13,293			(130,093		)	118,334
Net income attributable to noncontrolling interest	—			—			(808		)	—			(808		)
Net income attributable to Molycorp stockholders	$	117,526		$	117,608		$	12,485		$	(130,093	)	$	117,526
Net income	$	117,526		$	117,608		$	13,293		$	(130,093	)	$	118,334
Other comprehensive income:
Foreign currency translation adjustments	—			—			(8,481		)	—			(8,481		)
Comprehensive income	$	117,526		$	117,608		$	4,812		$	(130,093	)	$	109,853
Comprehensive income attributable to:
Molycorp stockholders	117,526			117,608			4,427			(130,093		)	109,468
Noncontrolling interest	—			—			385			—			385
	$	117,526		$	117,608		$	4,812		$	(130,093	)	$	109,853
Schedule of Condensed Cash Flow Statement	'
		Year Ended December 31, 2012
		(In thousands)
	Condensed Consolidating Statements of Cash Flows	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
	Net cash (used in) provided by operating activities	$	(13,207	)	$	(112,386	)	$	35,958		$	—		$	(89,635	)
	Cash flows from investing activities:
	Cash paid in connection with acquisitions, net of cash acquired	—			—			(591,011		)	—			(591,011		)
	Loans to subsidiaries	(683,063		)	—			—			683,063			—
	Loans to Parent	—			(37,589		)	—			37,589			—
	Intercompany advances made	(1,009,014		)	—			—			1,009,014			—
	Repayments from subsidiaries	87,824			—			—			(87,824		)	—
	Investment in subsidiaries	(350,000		)	—			—			350,000			—
	Notes receivable to non-guarantor	—			(227,512		)	—			227,512			—
	Repayments of notes receivable from non-guarantor	—			110,000			—			(110,000		)	—
	Investment in joint ventures	—			(27,680		)	(5,364		)	—			(33,044		)
	Deposits	—			(3,999		)	—			—			(3,999		)
	Capital expenditures	—			(766,951		)	(24,518		)	—			(791,469		)
	Acquisition of exploration rights	—			—			(8,167		)	—			(8,167		)
	Other investing activities	—			—			4,761			—			4,761
	Net cash used in investing activities	(1,954,253		)	(953,731		)	(624,299		)	2,109,354			(1,422,929		)
	Cash flows from financing activities:
	Capital contributions from stockholder	390,093			—			—			—			390,093
	Capital contributions from Parent	—			—			350,000			(350,000		)	—
	Repayments of debt	—			(870		)	(227,838		)	—			(228,708		)
	Net proceeds from sale of common stock	132,130			—			—			—			132,130
	Issuance of 10% Senior Secured Notes	635,373			—			—			—			635,373
	Issuance of 6.00% Convertible Notes	395,712			—			—			—			395,712
	Payments of preferred dividends	(11,385		)	—			—			—			(11,385		)
	Dividend paid to noncontrolling interests	—			—			(5,977		)	—			(5,977		)
	Proceeds from debt	—			—			14,699			—			14,699
	Borrowings from parent	—			227,512			455,551			(683,063		)	—
	Repayments of borrowings to parent	—			(34,327		)	(53,497		)	87,824			—
	Borrowing from guarantor	37,589			—			227,512			(265,101		)	—
	Repayments of borrowings to guarantor	—			—			(110,000		)	110,000			—
	Intercompany advances owed	—			881,179			127,835			(1,009,014		)	—
	Other financing activities	(2,938		)	(115		)	1,499			—			(1,554		)
	Net cash provided by financing activities	1,576,574			1,073,379			779,784			(2,109,354		)	1,320,383
	Effect of exchange rate changes on cash	—			—			1,116			—			1,116
	Net change in cash and cash equivalents	(390,886		)	7,262			192,559			—			(191,065		)
	Cash and cash equivalents at beginning of the period	407,446			10,758			651			—			418,855
	Cash and cash equivalents at end of period	$	16,560		$	18,020		$	193,210		$	—		$	227,790
		Year Ended December 31, 2011
		(In thousands)
	Condensed Consolidating Statements of Cash Flows	Parent			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Molycorp, Inc. consolidated
	Net cash provided by (used in) operating activities	$	903		$	44,211		$	(2,149	)	$	—		$	42,965
	Cash flows from investing activities:
	Cash paid in connection with acquisitions, net of cash acquired	—			(30,128		)	105			—			(30,023		)
	Cash paid to acquire non-marketable securities	—			(20,000		)	—			—			(20,000		)
	Loans to subsidiaries	(49,430		)	—			—			49,430			—
	Intercompany advances made	(290,633		)	—			—			290,633			—
	Deposits	16,449			(13,552		)	—			—			2,897
	Capital expenditures	—			(294,010		)	(8,170		)	—			(302,180		)
	Other investing activities	—			16			(100		)	—			(84		)
	Net cash used in investing activities	(323,614		)	(357,674		)	(8,165		)	340,063			(349,390		)
	Cash flows from financing activities:
	Repayments of short-term borrowings—related party	—			(3,150		)	—			—			(3,150		)
	Repayments of debt	—			—			(4,428		)	—			(4,428		)
	Net proceeds from sale of preferred stock	199,642			—			—			—			199,642
	Net proceeds from sale of Convertible Notes	223,100			—			—			—			223,100
	Payments of preferred dividends	(9,015		)	—			—			—			(9,015		)
	Proceeds from debt	—			—			5,131			—			5,131
	Intercompany advances owed	—			290,001			632			(290,633		)	—
	Net borrowings from parent	—			37,370			12,060			(49,430		)	—
	Net cash provided by financing activities	413,727			324,221			13,395			(340,063		)	411,280
Effect of exchange rate changes on cash	—			—			(2,430		)	—			(2,430		)
Net change in cash and cash equivalents	91,016			10,758			651			—			102,425
Cash and cash equivalents at beginning of the period	316,430			—			—			—			316,430
Cash and cash equivalents at end of period	$	407,446		$	10,758		$	651		$	—		$	418,855

Discontinued_Operations_Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	'
	As of December 31, 2013, the disposal group had the following carrying amounts, which were recorded under “Prepaid expenses and other current assets” in the consolidated balance sheet:
		31-Dec-13
		(In thousands)
	Land	$	25
	Buildings	250
	Equipment	250
	Inventory	475
	Carrying value of disposal group	$	1,000
	The following table summarizes the operating results of the Napanee facility included in discontinued operations for the years ended December 31, 2013 and 2012:
		December 31,			June 12 -December 31,
		2013			2012
		(In thousands)
	Revenues	$	2,091		$	1,214
	Costs of sales	(3,834		)	(2,691		)
	Selling, general and administrative expenses	(351		)	(232		)
	Depreciation	(28		)	(28		)
	Operating loss	(2,122		)	(1,737		)
	Loss on assets impairment	(4,305		)	—
	Income tax	—			—
	Net loss	$	(6,427	)	$	(1,737	)

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements, Recurring and Nonrecurring	'
	The Company's assets and liabilities measured at fair value on a recurring basis were as follows at December 31, 2013 and 2012:
		At December 31, 2013
		Quoted Prices in Active Markets for Identical Assets/Liabilities			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)				Total
		(In thousands)
	Assets:
	Cash equivalents	$	179,052		—			—				$	179,052
	Liabilities:
	Derivative liability	—			—			$	6,089			$	6,089
		At December 31, 2012
		Quoted Prices in Active Markets for Identical Assets/Liabilities			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)				Total
		(In thousands)
	Assets:
	Cash equivalents	$	58,253		—			—				$	58,253
	Liabilities:
	Derivative liability	—			—			$	7,816			$	7,816
Fair Value, by Balance Sheet Grouping	'
	The following table presents the fair value of financial liabilities the Company reports at their carrying value:
			At December 31, 2013							At December 31, 2012
		Classification	Carrying Value			Fair Value				Carrying Value				Fair Value
			(In thousands)
	Long-term debt
	3.25% Convertible Notes due June 2016	(Level 1)	$	207,028		$	161,771			$	198,689			$	159,542
	6.00% Convertible Notes due September 2017	(Level 1)	346,708			312,570				331,977				412,965
	5.50% Convertible Notes due February 2018	(Level 1)	148,198			164,015				n/a				n/a
	10% Senior Secured Notes due June 2020	(Level 1)	637,435			646,750				636,111				n/a
	Total long-term debt		$	1,339,369		$	1,285,106			$	1,166,777			$	572,507

Unaudited_Supplementary_Data_T

Unaudited Supplementary Data (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Schedule of Quarterly Financial Information	'
	The following is a summary of the selected quarterly financial information (unaudited):
		2013
		Quarter ended
		31-Mar		30-Jun		30-Sep		31-Dec
		(In thousands of dollars, except per share data)
	Revenues	145,398		136,112		149,066		123,814
	Gross profit (loss)	(4,305	)	(18,036	)	(17,778	)	(27,049	)
	Loss from continuing operations before income taxes and equity earnings (a)	(57,249	)	(70,254	)	(76,181	)	(228,592	)
	Net loss	(38,153	)	(70,689	)	(69,799	)	(198,288	)
	Net loss attributable to Molycorp stockholders	(38,971	)	(71,175	)	(69,929	)	(194,308	)
	Loss per share of common stock from continuing operations: (b)
	Basic	(0.27	)	(0.44	)	(0.43	)	(0.95	)
	Diluted	(0.27	)	(0.44	)	(0.43	)	(0.95	)
		2012
		Quarter ended
		31-Mar		30-Jun		30-Sep		31-Dec
		(In thousands of dollars, except per share data)
	Revenues	84,470		104,410		205,205		133,611
	Gross profit (loss)	31,027		(3,996	)	11,494		(19,703	)
	Loss from continuing operations before income taxes and equity earnings (c)	(5,434	)	(93,871	)	(42,984	)	(381,902	)
	Net loss	(3,478	)	(66,924	)	(15,451	)	(389,490	)
	Net loss attributable to Molycorp stockholders	(3,478	)	(67,604	)	(18,891	)	(391,196	)
	Loss per share of common stock from continuing operations: (b)
	Basic	(0.07	)	(0.71	)	(0.19	)	(3.16	)
	Diluted	(0.07	)	(0.71	)	(0.19	)	(3.16	)
	(a)	Includes the following impairment charges in the fourth quarter: goodwill, $11.0 million; rare earths quotas, $67.2 million; patents, $10.2 million; exploration rights, $16.2 million; cost-method investments $9.4 million and long-lived tangible assets, $16.3 million.
	(b)	The sum of the quarterly income (loss) per share may be different than the per share amount for the year as the calculation for each quarter is based on the weighted average shares outstanding for that period.
	(c)	Includes the following impairment charges in the fourth quarter: goodwill, $287.9 million; patents, $6.0 million; and long-lived tangible assets, $5.9 million.

Company_Background_Narrative_D

Company Background Narrative (Details)	Dec. 31, 2013
	location
	country
	continent
	employee
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Number of continents in which entity operates	3
Number of employees	2,600
Number of worldwide locations	26
Number of countries in which entity operates	11

Recovered_Sheet1

Summary of significant accounting policies (Details) (USD $)

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Molycorp Canada

Magnetic Materials and Alloys

Magnetic Materials and Alloys

Resources

Resources

Rare Metals

Rare Metals

Customer relationships

Customer relationships

Chinese Land Use Rights

Chinese Land Use Rights

Rare earths quotas

Rare earths quotas

Patents

Patents

Trade names

Minimum

Minimum

Minimum

Minimum

Maximum

Maximum

Maximum

Maximum

Buildings and improvements

Buildings and improvements

Plant and equipment

Plant and equipment

Customer relationships

Rare earths quotas

Patents

Trade names

Customer relationships

Rare earths quotas

Patents

Trade names

Minimum

Maximum

Minimum

Maximum

Property, Plant and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for doubtful accounts

$2,600,000

$2,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment useful life

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'40 years

'2 years

'15 years

Finite-lived intangible asset useful life

'

'

'

'

'

'

'

'

'

'

'

'

'50 years

'

'

'

'

'

'

'2 years

'2 years

'2 years

'2 years

'16 years

'16 years

'16 years

'16 years

'

'

'

'

Property, plant and equipment, net

1,762,874,000

1,762,874,000

1,544,304,000

'

'

'

'

14,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of finite-lived intangible assets

'

'

6,000,000

'

'

'

'

'

'

'

0

0

0

0

78,300,000

0

33,100,000

6,000,000

0

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of long-lived assets to be disposed of

'

'

'

'

'

'

3,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of goodwill and other intangible assets

11,000,000

10,992,000

289,894,000

287,900,000

0

112,694,000

'

'

10,992,000

16,068,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Valuation allowance

($107,358,000)

($107,358,000)

($20,631,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liquidity_and_Capital_Requirem1

Liquidity and Capital Requirements (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Capital Expenditures [Line Items]	'	'	'	'
Cash and cash equivalents	$314,317,000	$227,790,000	$418,855,000	$316,430,000
Molycorp Mountain Pass facility	'	'	'	'
Capital Expenditures [Line Items]	'	'	'	'
Capital expenditures in 2014	65,000,000	'	'	'
Capital expenditures in 2015	50,000,000	'	'	'
Expansion Capital Expenditures | Minimum	'	'	'	'
Capital Expenditures [Line Items]	'	'	'	'
Capital expenditures in 2014	20,000,000	'	'	'
Expansion Capital Expenditures | Maximum	'	'	'	'
Capital Expenditures [Line Items]	'	'	'	'
Capital expenditures in 2014	$25,000,000	'	'	'

Segment_Information_Details

Segment Information (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

segment

Segment Information

'

'

'

'

'

'

'

'

'

'

'

Number of segments

'

'

'

'

'

'

'

'

4

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

$554,390

$527,696

$396,831

Total revenues

123,814

149,066

136,112

145,398

133,611

205,205

104,410

84,470

554,390

527,696

396,831

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-105,764

-52,808

-15,227

Operating loss (e)

'

'

'

'

'

'

'

'

-356,691

[1]

-466,149

[1]

152,866

Loss before income taxes and equity earnings

-228,592

[2]

-76,181

[2]

-70,254

[2]

-57,249

[2]

-381,902

[3]

-42,984

[3]

-93,871

[3]

-5,434

[3]

-432,276

-524,191

146,910

Total assets

3,006,802

'

'

'

2,992,535

'

'

'

3,006,802

2,992,535

1,255,125

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

249,487

[4]

843,061

[4]

409,217

[4]

Resources

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

33,621

'

'

Total revenues

'

'

'

'

'

'

'

'

59,661

'

'

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-46,318

'

'

Operating loss (e)

'

'

'

'

'

'

'

'

-223,702

[1]

'

'

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

-231,944

'

'

Total assets

1,791,421

'

'

'

'

'

'

'

1,791,421

'

'

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

231,027

[4]

'

'

Chemicals and Oxides

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

181,815

'

'

Total revenues

'

'

'

'

'

'

'

'

219,071

'

'

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-22,754

'

'

Operating loss (e)

'

'

'

'

'

'

'

'

-87,889

[1]

'

'

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

-87,848

'

'

Total assets

485,642

'

'

'

'

'

'

'

485,642

'

'

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

6,961

[4]

'

'

Magnetic Materials and Alloys

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

252,713

'

'

Total revenues

'

'

'

'

'

'

'

'

252,713

'

'

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-27,812

'

'

Operating loss (e)

'

'

'

'

'

'

'

'

23,087

[1]

'

'

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

62,107

'

'

Total assets

590,516

'

'

'

'

'

'

'

590,516

'

'

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

3,700

[4]

'

'

Rare Metals

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

86,241

'

'

Total revenues

'

'

'

'

'

'

'

'

86,241

'

'

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-8,652

'

'

Operating loss (e)

'

'

'

'

'

'

'

'

-21,108

[1]

'

'

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

-18,326

'

'

Total assets

82,538

'

'

'

'

'

'

'

82,538

'

'

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

7,549

[4]

'

'

Intersegment Eliminations

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

0

[5]

0

[5]

0

[5]

Total revenues

'

'

'

'

'

'

'

'

-63,296

[5]

-32,973

[5]

-69,057

[5]

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

0

[5]

0

[5]

0

[5]

Operating loss (e)

'

'

'

'

'

'

'

'

-953

[1],[5]

24,803

[1],[5]

-27,443

[5]

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

-953

[5]

24,803

[5]

-27,443

[5]

Total assets

-1,490,582

[5]

'

'

'

-737,276

[5]

'

'

'

-1,490,582

[5]

-737,276

[5]

-143,730

[5]

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

0

[4],[5]

0

[4],[5]

0

[4],[5]

Operating Segments | Resources

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

'

88,870

253,563

Total revenues

'

'

'

'

'

'

'

'

'

96,126

308,718

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

'

-13,991

-10,553

Operating loss (e)

'

'

'

'

'

'

'

'

'

-70,220

[1]

218,549

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

'

-70,469

218,391

Total assets

'

'

'

'

1,802,842

'

'

'

'

1,802,842

824,712

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

'

814,054

[4]

401,047

[4]

Operating Segments | Chemicals and Oxides

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

'

181,849

40,216

Total revenues

'

'

'

'

'

'

'

'

'

207,566

54,118

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

'

-13,110

-1,958

Operating loss (e)

'

'

'

'

'

'

'

'

'

-191,059

[1]

8,700

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

'

-190,094

5,785

Total assets

'

'

'

'

639,847

'

'

'

'

639,847

46,368

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

'

10,910

[4]

8,170

[4]

Operating Segments | Magnetic Materials and Alloys

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

'

179,335

56,772

Total revenues

'

'

'

'

'

'

'

'

'

179,335

56,772

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

'

-19,737

-236

Operating loss (e)

'

'

'

'

'

'

'

'

'

-125,543

[1]

2,331

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

'

-126,981

2,336

Total assets

'

'

'

'

593,197

'

'

'

'

593,197

30,061

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

'

5,614

[4]

0

[4]

Operating Segments | Rare Metals

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

'

77,642

[6]

46,280

Total revenues

'

'

'

'

'

'

'

'

'

77,642

[6]

46,280

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

'

-5,837

[6]

-2,449

Operating loss (e)

'

'

'

'

'

'

'

'

'

-18,671

[1],[6]

2,131

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

'

-18,181

[6]

-634

Total assets

'

'

'

'

117,961

[6]

'

'

'

'

117,961

[6]

71,634

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

'

10,750

[4],[6]

0

[4]

Corporate and other | Corporate and other

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-228

[7]

-133

[7]

-31

[7]

Operating loss (e)

'

'

'

'

'

'

'

'

-46,126

[1],[7]

-85,459

[1],[7]

-51,402

[7]

Loss before income taxes and equity earnings

'

'

'

'

'

'

'

'

-155,312

[7]

-143,269

[7]

-51,525

[7]

Total assets

1,547,267

[7]

'

'

'

575,964

[7]

'

'

'

1,547,267

[7]

575,964

[7]

426,080

[7]

Property, Plant and Equipment, Additions

'

'

'

'

'

'

'

'

250

[4],[7]

1,733

[4],[7]

0

[4],[7]

Intersegment Eliminations

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

0

0

0

Intercompany Costs

'

'

'

'

'

'

'

'

62,343

57,776

41,614

Intersegment Eliminations | Resources

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

26,040

7,256

55,155

Intersegment Eliminations | Chemicals and Oxides

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

37,256

25,717

13,902

Intersegment Eliminations | Magnetic Materials and Alloys

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

0

'

0

Intersegment Eliminations | Rare Metals

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

0

'

[6]

0

Intersegment Eliminations | Intersegment Eliminations

'

'

'

'

'

'

'

'

'

'

'

Sales:

'

'

'

'

'

'

'

'

'

'

'

Revenues:

'

'

'

'

'

'

'

'

($63,296)

[5]

($32,973)

[5]

($69,057)

[5]

[1]

Includes impairment of goodwill and other long-lived assets in some segments. See notes 7 and 9 below for details.

[2]

Includes the following impairment charges in the fourth quarter: goodwill, $11.0 million; rare earths quotas, $67.2 million; patents, $10.2 million; exploration rights, $16.2 million; cost-method investments $9.4 million and long-lived tangible assets, $16.3 million.

[3]

The sum of the quarterly income (loss) per share may be different than the per share amount for the year as the calculation for each quarter is based on the weighted average shares outstanding for that period.

[4]

On an accrual basis excluding capitalized interest.

[5]

The net elimination in operating results includes costs of sales eliminations of $62,343, $57,776 and $41,614 for the years ended December 31, 2013, 2012 and 2011, respectively, which consist of intercompany gross profits as well as eliminations of lower of cost or market adjustments related to intercompany inventory. The total assets elimination is comprised primarily of intercompany investments and intercompany accounts receivable and profits in inventory.

[6]

Excludes operating results from the Napanee facility, which is treated as a discontinued operation for comparative purposes.

[7]

Corporate and other loss before income taxes and equity earnings includes business development costs, personnel costs, stock-based compensation, accounting and legal fees, occupancy expense, information technology costs and interest expense. Total Corporate and other assets is comprised primarily of cash and cash equivalents.

Revenue_and_Longlived_Assets_b

Revenue and Long-lived Assets by Location (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	$554,390	$527,696	$396,831
Long-lived assets	1,762,874	1,544,304	'
China	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	199,021	118,086	421
Long-lived assets	53,131	52,914	'
Japan	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	99,952	160,942	204,262
Thailand	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	17,129	7,674	0
Long-lived assets	6,213	5,902	'
Other Asia	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Long-lived assets	1,913	18,221	'
Hong Kong	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	8,815	4,793	0
South Korea	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	12,418	3,828	0
Singapore	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	54	212	0
North America	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	92,066	103,555	128,544
Long-lived assets	1,627,892	1,391,690	'
Europe	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	113,549	117,907	56,760
Long-lived assets	73,674	75,495	'
Other	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Revenues:	11,386	10,699	6,844
Long-lived assets	$51	$82	'

Inventory_Details

Inventory (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current:	'	'	'
Concentrate stockpiles	$24,000	$6,393,000	'
Raw materials	42,627,000	95,248,000	'
Work in process	41,962,000	55,229,000	'
Finished goods	65,662,000	114,903,000	'
Materials and supplies	21,508,000	15,603,000	'
Total current	171,783,000	287,376,000	'
Long-term:	'	'	'
Concentrate stockpiles	4,000	4,000	'
Raw materials	25,325,000	26,092,000	'
Total long-term	25,329,000	26,096,000	'
Production costs expensed that would have been allocated to additional tons produced, assuming operations at normal production rates	88,100,000	12,000,000	4,300,000
Inventory write-downs	100,300,000	80,900,000	2,800,000
Stockpile Inventory Write Down	'	$2,100,000	$2,300,000

Deposits_Details

Deposits (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deposits [Line Items]	'	'
Deposits	$25,997	$26,769
Deposits related to construction insurance program	1,504	1,504
Other restricted cash requirements related to deposits	3,881	4,653
Kern River Gas Transmission Company	'	'
Deposits [Line Items]	'	'
Escrow deposit	$20,612	$20,612

Property_Plant_and_Equipment_n2

Property, Plant and Equipment, net (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Molycorp Silmet

Resources

Resources

Assets Held under Capital Leases

Assets Held under Capital Leases

Land

Land

Land improvements

Land improvements

Land improvements

Land improvements

Buildings and improvements

Buildings and improvements

Buildings and improvements

Buildings and improvements

Plant and equipment

Plant and equipment

Plant and equipment

Plant and equipment

Vehicles

Vehicles

Computer software

Computer software

Furnitures and fixtures

Furnitures and fixtures

Construction in progress

Construction in progress

Natural gas delivery facility under capital lease

Natural gas delivery facility under capital lease

Mining equipment under capital lease

Mining equipment under capital lease

Mineral properties

Mineral properties

Exploration rights

Exploration rights

Exploration rights

Minimum

Maximum

Minimum

Maximum

Minimum

Maximum

Property, Plant and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalized expenditures

$320,700,000

$902,300,000

$416,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalized interest related to plant modernization and other capitalized costs

71,200,000

59,300,000

7,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Depreciation expense

60,300,000

20,900,000

14,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment at cost

1,865,552,000

1,589,235,000

'

'

'

'

'

'

12,822,000

12,475,000

327,029,000

63,269,000

'

'

418,510,000

237,379,000

'

'

288,603,000

194,934,000

'

'

2,986,000

2,842,000

12,424,000

9,528,000

1,044,000

1,116,000

755,107,000

[1]

1,011,541,000

[1]

'

'

'

'

23,999,000

24,327,000

0

0

16,166,000

Capital Leased Assets, Gross

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,658,000

15,658,000

7,370,000

0

'

'

'

'

'

Less accumulated depreciation

-102,678,000

-44,931,000

'

'

'

'

-2,300,000

-900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment, net

1,762,874,000

1,544,304,000

'

'

'

14,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Useful life

'

'

'

'

'

'

'

'

'

'

'

'

'15 years

'30 years

'

'

'4 years

'40 years

'

'

'2 years

'15 years

'7 years

'

'5 years

'

'5 years

'

'

'

'10 years

'

'7 years

'

'

'

'

'

'

Tangible Asset Impairment Charges

16,300,000

5,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

16,200,000

16,200,000

'

Impairment of long-lived assets to be disposed of

'

'

'

$2,000,000

$3,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

at the Molycorp Mountain Pass facility

Mineral_Properties_Development1

Mineral Properties, Development Costs and Exploration Rights Narrative (Details) (USD $)	3 Months Ended	12 Months Ended			3 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
					Exploration rights	Exploration rights	Exploration rights
Property, Plant and Equipment [Line Items]	'	'	'	'	'	'	'
Property, plant and equipment at cost	$1,589,235,000	$1,865,552,000	$1,589,235,000	'	$0	$16,166,000	$0
Purchase price for exploration right	1,589,235,000	1,865,552,000	1,589,235,000	'	0	16,166,000	0
Issuance of shares for investment in mining property	'	'	'	'	'	788,410	'
Sale of stock, price per share	'	'	'	'	'	$10.15	'
Payments to acquire exploration rights	8,200,000	0	8,167,000	0	'	'	'
Tangible Asset Impairment Charges	'	$16,300,000	$5,900,000	'	$16,200,000	'	$16,200,000

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets Narrative (Details) (USD $)

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Molycorp Canada

Rare Metals

Rare Metals

Magnetic Materials and Alloys

Magnetic Materials and Alloys

Patents

Patents

Patents

Rare earths quotas

Rare earths quotas

Rare earths quotas

Goodwill [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of goodwill and other intangible assets

$11,000,000

$10,992,000

$289,894,000

'

$287,900,000

$10,992,000

$16,068,000

$0

$112,694,000

'

'

'

'

'

'

Goodwill, impairment loss from initial purchase price allocation

'

'

258,300,000

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill, additional impairment loss from final purchase price allocation

'

'

'

'

31,600,000

'

'

'

'

'

'

'

'

'

'

Impairment of goodwill and other long-lived assets

'

120,898,000

301,755,000

0

'

'

'

'

'

10,200,000

'

'

67,200,000

'

'

Impairment of finite-lived intangible assets

'

'

6,000,000

'

'

'

'

'

'

'

33,100,000

6,000,000

'

78,300,000

0

Amortization expense

'

$43,556,000

$28,579,000

$236,000

'

'

'

'

'

'

$13,554,000

$9,365,000

'

$7,018,000

$4,035,000

Goodwill_Rollforward_Details

Goodwill Rollforward (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill [Roll Forward]	'	'	'	'
Beginning of period	'	$239,742	$3,432	$0
Goodwill acquired	'	'	526,204	3,432
Impairment	-11,000	-10,992	-289,894	'
End of period	228,750	228,750	239,742	3,432
Chemicals and Oxides	'	'	'	'
Goodwill [Roll Forward]	'	'	'	'
Beginning of period	'	125,229	728	0
Goodwill acquired	'	'	285,633	728
Impairment	'	0	-161,132	'
End of period	125,229	125,229	125,229	728
Magnetic Materials and Alloys	'	'	'	'
Goodwill [Roll Forward]	'	'	'	'
Beginning of period	'	102,808	1,977	0
Goodwill acquired	'	'	213,525	1,977
Impairment	'	0	-112,694	'
End of period	102,808	102,808	102,808	1,977
Rare Metals	'	'	'	'
Goodwill [Roll Forward]	'	'	'	'
Beginning of period	'	11,705	727	0
Goodwill acquired	'	'	27,046	727
Impairment	'	-10,992	-16,068	'
End of period	$713	$713	$11,705	$727

Intangible_Asset_Rollforward_D

Intangible Asset Rollforward (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period start	$479,900	$3,455	'
Additions	48	482,445	'
Foreign currency translation adjustment	-242	'	'
Impairment	'	-6,000	'
Impairment	-111,400	'	'
At period end	368,306	479,900	3,455
At period start	28,962	383	'
Adjustments	-1,134	'	'
Amortization	43,556	28,579	236
Impairment	-33,945	'	'
At period end	37,439	28,962	383
Net book value	330,867	450,938	'
Trade names	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period end	15,586	15,586	'
Net book value	15,243	14,434	'
Trade names	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
Additions	0	14,800	'
Customer relationships	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period start	344,774	2,669	'
Additions	48	342,105	'
Foreign currency translation adjustment	-242	'	'
Impairment	0	0	'
At period end	344,580	344,774	'
At period start	14,095	170	'
Adjustments	-260	'	'
Amortization	22,145	13,925	'
Impairment	0	'	'
At period end	35,980	14,095	'
Net book value	308,600	330,679	'
Rare earths quotas	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period start	78,300	0	'
Additions	0	78,300	'
Foreign currency translation adjustment	0	'	'
Impairment	-78,300	0	'
At period end	0	78,300	'
At period start	4,035	0	'
Adjustments	0	'	'
Amortization	7,018	4,035	'
Impairment	-11,053	'	'
At period end	0	4,035	'
Net book value	0	74,265	'
Patents	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period start	33,252	0	'
Additions	0	39,252	'
Foreign currency translation adjustment	0	'	'
Impairment	-33,100	-6,000	'
At period end	152	33,252	'
At period start	9,365	0	'
Adjustments	0	'	'
Amortization	13,554	9,365	'
Impairment	-22,892	'	'
At period end	27	9,365	'
Net book value	125	23,887	'
Trade names	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period start	15,586	786	'
Foreign currency translation adjustment	0	'	'
Impairment	'	0	'
Impairment	0	'	'
At period end	'	15,586	'
At period start	1,152	213	'
Adjustments	-874	'	'
Amortization	65	939	'
Impairment	0	'	'
At period end	343	1,152	'
Land use rights	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period start	3,568	0	'
Additions	0	3,568	'
Foreign currency translation adjustment	0	'	'
Impairment	0	0	'
At period end	3,568	3,568	'
At period start	66	0	'
Adjustments	0	'	'
Amortization	161	66	'
Impairment	0	'	'
At period end	227	66	'
Net book value	3,341	3,502	'
Other	'	'	'
Finite-Lived and Indefinite-lived Intangible Assets [Roll Forward]	'	'	'
At period start	4,420	0	'
Additions	0	4,420	'
Foreign currency translation adjustment	0	'	'
Impairment	0	0	'
At period end	4,420	4,420	'
At period start	249	0	'
Adjustments	0	'	'
Amortization	613	249	'
Impairment	0	'	'
At period end	862	249	'
Net book value	$3,558	$4,171	'

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets Future Amortization Schedule (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'
2014	$23,816
2015	23,789
2016	23,740
2017	23,740
2018	23,576
Thereafter	$197,406

Schedule_of_Equity_and_Cost_Me

Schedule of Equity and Cost Method Investments (Details) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

24 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Sep. 13, 2011

Dec. 31, 2013

Dec. 31, 2012

Mar. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Boulder Wind Power, Inc.

Boulder Wind Power, Inc.

Boulder Wind Power, Inc.

Intermetallics Japan

Intermetallics Japan

Intermetallics Japan

Intermetallics Japan

Keli

Keli

Ingal Stade

Ingal Stade

Other investments at cost

Other investments at cost

Equity and Cost Method Investment [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning of period

'

'

'

'

'

$20,000,000

$20,000,000

'

'

'

'

'

'

'

'

$2,828,000

$0

Additions

'

0

0

20,000,000

20,000,000

0

0

'

'

'

'

'

'

'

'

0

2,828,000

Impairment

-9,400,000

-9,411,000

0

0

'

-8,000,000

'

'

'

'

'

'

'

'

'

-1,411,000

[1]

'

End of period

'

'

'

'

'

12,000,000

20,000,000

'

'

'

'

'

'

'

'

1,417,000

2,828,000

Beginning of period

'

0

'

'

'

'

'

25,193,000

25,193,000

0

0

11,000,000

0

5,015,000

0

'

'

Additions

'

3,419,000

47,526,000

'

'

'

'

3,400,000

3,419,000

27,598,000

31,000,000

0

12,200,000

0

4,900,000

'

'

Equity loss

'

-9,169,000

-3,490,000

0

'

'

'

'

-6,529,000

-2,405,000

'

-2,600,000

-1,200,000

-40,000

115,000

'

'

Impairment

'

'

'

'

'

'

'

'

0

'

'

0

'

0

'

'

'

End of period

0

0

0

'

'

'

'

'

22,083,000

25,193,000

22,083,000

8,400,000

11,000,000

4,975,000

5,015,000

'

'

Beginning of period

'

64,036,000

20,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment

'

-9,411,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

End of period

$48,875,000

$48,875,000

$64,036,000

$20,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The impairment charge in 2013 relates to the disposal of the equity interest in Atlantic Metals & Alloys, LLC.

Investments_Details

Investments (Details) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

24 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Sep. 13, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Nov. 28, 2011

Nov. 28, 2011

Nov. 28, 2011

Dec. 31, 2013

Dec. 31, 2012

Jun. 12, 2012

Dec. 31, 2013

Dec. 31, 2012

Jun. 12, 2012

Boulder Wind Power, Inc.

Boulder Wind Power, Inc.

Boulder Wind Power, Inc.

Boulder Wind Power, Inc.

Boulder Wind Power, Inc.

Intermetallics Japan

Intermetallics Japan

Intermetallics Japan

Intermetallics Japan

Intermetallics Japan

Intermetallics Japan

Intermetallics Japan

Keli

Keli

Keli

Ingal Stade

Ingal Stade

Ingal Stade

Other Expense (Income)

Daido

Mitsubishi

Molycorp

Schedule of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment in Boulder Wind Power's Series B convertible preferred stock

'

$0

$0

$20,000,000

$20,000,000

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cost method investments

'

'

'

'

'

12,000,000

20,000,000

20,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment

9,400,000

9,411,000

0

0

'

8,000,000

'

'

8,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital contribution ratio (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

35.50%

34.50%

30.00%

'

'

25.00%

'

'

50.00%

Additions

'

3,419,000

47,526,000

'

'

'

'

'

'

3,400,000

3,419,000

27,598,000

31,000,000

'

'

'

0

12,200,000

'

0

4,900,000

'

Fair Value of the Equity Investment of a Business Acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$12,200,000

'

'

$4,900,000

Acquisitions_Narrative_Details

Acquisitions Narrative (Details)

1 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

0 Months Ended

3 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

1 Months Ended

Jun. 30, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Mar. 28, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Jun. 12, 2012

Apr. 02, 2011

Oct. 24, 2011

Apr. 11, 2011

Oct. 24, 2011

Apr. 02, 2011

Apr. 02, 2011

Dec. 31, 2011

Apr. 15, 2011

Apr. 15, 2011

Jun. 30, 2012

Jun. 30, 2012

Jun. 12, 2012

Jun. 11, 2012

Jun. 30, 2012

Jun. 12, 2012

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

CAD

JAMR

JAMR

Molycorp Canada

Molycorp Canada

Molycorp Canada

Molycorp Canada

Molycorp Canada

Molycorp Silmet

Molycorp Silmet

Molycorp Silmet

Molycorp Silmet

Molycorp Silmet

Molycorp Silmet

Molycorp Silmet and MMA

MMA

Santoku

MCP Exchangeco Inc.

MCP Exchangeco Inc.

MCP Exchangeco Inc.

Molycorp

Molycorp

Molycorp

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

CAD

USD ($)

Mg

AS Silmet Grupp

AS Silmet Grupp

Treibacher Industries AG

USD ($)

USD ($)

USD ($)

Molycorp Canada

Molycorp Canada

Molycorp Canada

Molycorp Canada

USD ($)

USD ($)

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Percentage of Voting Interests Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

90.02%

'

80.00%

1002.30%

'

'

'

'

'

'

'

'

'

Purchase of additional interest by parent, percentage

'

'

'

'

'

'

'

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ownership of subsidiary after purchase of additional interest

'

'

'

'

'

'

'

95.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase of additional interest by parent

'

'

'

'

'

'

'

$15,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase of additional interest by parent, cash portion

'

'

'

'

'

'

9,600,000

5,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase of additional interest by parent, cash portion, interest

'

'

'

'

'

'

200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash consideration paid for Molycorp Canada (in CAD per share)

'

'

'

'

'

'

'

'

'

'

'

'

11.3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share consideration paid for Molycorp Canada (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.4242

'

'

0.4242

Notional amount of derivatives

'

'

'

'

'

870,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued to acquire the entity (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

1,593,419

'

'

'

'

'

'

'

'

507,203

507,203

'

13,545,426

13,545,426

'

Cash consideration

'

'

'

'

'

'

'

'

908,181,000

908,181,000

'

'

'

9,021,000

'

'

'

'

9,000,000

'

17,500,000

17,500,000

'

'

'

'

'

'

Fair value of Molycorp common stock issued

284,100,000

'

'

'

'

'

'

'

284,144,000

284,144,000

'

'

'

72,653,000

'

'

'

'

'

'

0

'

'

'

'

'

'

'

Total purchase consideration

'

'

'

'

'

'

'

'

1,192,325,000

1,192,325,000

'

'

'

81,674,000

'

'

'

'

'

'

17,500,000

'

'

'

'

'

'

'

Goodwill, additional impairment loss from final purchase price allocation

'

'

'

'

'

'

'

'

'

'

31,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of goodwill and other intangible assets

'

11,000,000

10,992,000

289,894,000

'

'

'

'

'

'

287,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Assets, Useful Life, Minimum

'

'

'2 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Assets, Useful Life, Maximum

'

'

'30 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Direct Transaction Expenses Excluded from Nonrecurring Expense

'

'

'

115,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Recognized Transaction Costs

'

'

'

62,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Intercompany sales

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

69,100,000

'

'

'

'

'

'

'

'

Intercompany earnings

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28,000,000

'

'

'

'

'

'

'

'

Acquisition related costs

'

'

247,000

19,796,000

5,912,000

'

'

'

'

'

'

16,498,000

'

'

'

'

'

'

'

2,100,000

'

'

'

'

'

'

'

'

Purchase price variance

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,100,000

'

'

'

'

'

'

'

'

Value of shares issued

'

'

'

'

'

'

'

'

'

'

'

'

'

80,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of consecutive trading days

'

'

'

'

'

'

'

'

'

'

'

'

'

'20 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Discount percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

23.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Step acquisition, equity interest in acquiree

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.98%

9.98%

'

'

'

'

'

'

'

'

'

'

Step acquisition, fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,000,000

'

'

'

'

'

'

'

'

'

'

'

Adjustments to paid in capital for the difference between the consideration paid and the carrying value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

400,000

'

'

'

'

'

'

'

'

'

'

'

Increase in production capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Marketing and distribution agreement period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

Rare earth products purchase and supply agreement period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2 years

'

'

'

'

'

'

Business Acquisition, Transaction Costs [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Corporate development: Legal, accounting and advisory fees

'

'

247,000

19,796,000

5,912,000

'

'

'

'

'

'

16,498,000

'

'

'

'

'

'

'

2,100,000

'

'

'

'

'

'

'

'

Other expenses: Contingent forward contract loss

'

'

'

'

'

'

'

'

'

'

'

37,589,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest expense: Bridge loan fee

'

'

'

'

'

'

'

'

'

'

'

$7,937,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Schedule_of_Acquisitions_Detai

Schedule of Acquisitions (Details) (USD $)	1 Months Ended	0 Months Ended		12 Months Ended		0 Months Ended					12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Apr. 02, 2011	Apr. 15, 2011	Dec. 31, 2011
		Molycorp Canada	Molycorp Canada	Molycorp Canada	Molycorp Canada	Molycorp Canada	Molycorp Canada	Molycorp Canada	Molycorp Silmet	MMA	Molycorp Silmet and MMA
						Measurement Period Adjustments	Preliminary Allocation of Consideration Transferred as of December 31, 2012	Final Allocation of Consideration Transferred
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Cash consideration	'	$908,181	$908,181	'	'	'	'	'	$9,021	$17,500	'
Fair value of Molycorp common stock and Exchangeable Shares issued	284,100	284,144	284,144	'	'	'	'	'	72,653	0	'
Total purchase consideration	'	1,192,325	1,192,325	'	'	0	1,192,325	1,192,325	81,674	17,500	'
Cash and cash equivalents	'	'	'	'	'	0	317,169	317,169	105	6,395	'
Restricted cash	'	'	'	'	'	0	4,951	4,951	'	'	'
Accounts receivable	'	'	'	'	'	0	101,470	101,470	'	'	'
Accounts receivable and other current assets	'	'	'	'	'	'	'	'	8,626	5,474	'
Inventory	'	'	'	'	'	0	250,989	250,989	37,404	11,327	'
Prepaid expenses and other current assets	'	'	'	'	'	0	26,893	26,893	'	'	'
Property, plant and equipment	'	'	'	'	'	0	75,745	75,745	63,393	4,512	'
Investments	'	'	'	'	'	-1,091	21,019	19,928	'	'	'
Intangibles	'	'	'	'	'	0	482,234	482,234	2,669	0	'
Deferred tax charges	'	'	'	'	'	0	13,435	13,435	'	'	'
Deferred tax assets	'	'	'	'	'	-1,423	11,473	10,050	'	'	'
Goodwill	'	'	'	'	'	31,616	494,809	526,425	1,455	1,977	'
Other non-current assets	'	'	'	'	'	0	4,367	4,367	'	'	'
Accounts payable and accrued expenses	'	'	'	'	'	0	-138,576	-138,576	-19,974	-8,989	'
Debt	'	'	'	'	'	0	-255,338	-255,338	'	'	'
Deferred tax liabilities	'	'	'	'	'	5,880	-154,309	-148,429	0	-3,196	'
Long-term debt	'	'	'	'	'	'	'	'	-3,184	0	'
Other non-current liabilities	'	'	'	'	'	0	-14,255	-14,255	'	'	'
Non-controlling interests	'	'	'	'	'	-34,982	-15,761	-50,743	-8,820	0	'
Other current liabilities	'	'	'	'	'	0	-33,990	-33,990	'	'	'
Unaudited proforma	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	863,728	1,196,876	'	'	'	'	'	430,305
Net income (loss)	'	'	'	-463,716	241,903	'	'	'	'	'	105,397
Net income (loss) attributable to Molycorp	'	'	'	($473,249)	$231,772	'	'	'	'	'	$104,590
EPS Basic (in dollars per share)	'	'	'	($4.53)	$2.66	'	'	'	'	'	$1.13

Accrued_Expenses_Details

Accrued Expenses (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accrued Expenses	'	'
Defined contribution plan	$1,921	$1,400
Professional fees	135	4,971
Accrued payroll and related benefits	5,739	7,532
Sales and use tax	3,354	7,187
Bonus accrual	4,449	3,503
Interest payable	18,158	15,253
Advance from customer	600	1,753
Withholding taxes	2,563	2,929
Amount payable to noncontrolling interest	352	9,640
Other accrued expenses	11,230	4,845
Total accrued expenses	$48,501	$59,013

Asset_Retirement_Obligation_De

Asset Retirement Obligation (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Asset retirement obligation activity	'	'	'
Balance at beginning of period	$22,125,000	$15,541,000	'
Obligations settled	-3,849,000	-2,954,000	'
Accretion expense	1,328,000	1,299,000	'
Revisions in estimated cash flows	-3,793,000	7,872,000	'
Loss on settlement	1,772,000	367,000	'
Balance at end of period	17,583,000	22,125,000	15,541,000
Asset Retirement Obligation [Abstract]	'	'	'
Asset retirement obligation, current	600,000	3,500,000	'
Depreciation expense	2,500,000	2,000,000	1,000,000
Financial assurance requirement satisfied with surety bonds	28,800,000	'	'
Resources	'	'	'
Asset retirement obligation activity	'	'	'
Revisions in estimated cash flows	'	3,800,000	'
Demolition and Reclamation of the Old Mill and Mineral Recovery Areas at the Molycorp Mountain Pass Facility	'	'	'
Asset retirement obligation activity	'	'	'
Revisions in estimated cash flows	'	$4,100,000	'

Debt_and_Capital_Lease_Obligat2

Debt and Capital Lease Obligations (Details) (USD $)

0 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

Oct. 21, 2013

Jan. 30, 2013

Dec. 31, 2013

Dec. 31, 2013

Jun. 01, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jan. 30, 2013

Dec. 31, 2013

Jan. 30, 2013

Aug. 22, 2012

Dec. 31, 2013

Dec. 31, 2012

Aug. 31, 2012

Jun. 15, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Aug. 31, 2012

Jun. 12, 2012

Aug. 31, 2012

25-May-12

25-May-12

25-May-12

25-May-12

Dec. 31, 2013

Mining equipment under capital lease

Assets Held under Capital Leases

Notes Payable to Banks

Notes Payable to Banks

Senior Notes

Senior Notes

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Subordinated Debt

Convertible Subordinated Debt

Convertible Subordinated Debt

Convertible Subordinated Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

capital_lease

Bank Loans Due September 2017

Bank Loans Due September 2017

10% Senior Securied Notes, net of discount, due June 2020

10% Senior Securied Notes, net of discount, due June 2020

5.50% Convertible Senior Notes due 2018

5.50% Convertible Senior Notes due 2018

5.50% Convertible Senior Notes due 2018

6.00% Convertible Notes

6.00% Convertible Notes

6.00% Convertible Notes

6.00% Convertible Notes

3.25% Convertible Notes

3.25% Convertible Notes

3.25% Convertible Notes

3.25% Convertible Notes

5.00% Debentures, net of discount

5.00% Debentures, net of discount

5.00% Debentures, net of discount

5.00% Debentures, net of discount

Before June 1, 2016

After June 1, 2016

Before June 1, 2015

10% Senior Securied Notes, net of discount, due June 2020

10% Senior Securied Notes, net of discount, due June 2020

D

Officers, Directors and Other Related Parties

D

Common Stock

Common Stock

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average interest rate

'

'

'

'

'

3.59%

3.57%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unused portion of line of credit

'

'

$23,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Fiscal Year Maturity [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2014

'

'

14,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2015

'

'

1,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2016

'

'

230,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2017

'

'

414,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2018

'

'

175,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Thereafter

'

'

650,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest cost

'

'

'

'

'

'

'

66,323,000

[1]

40,070,000

[1]

'

13,107,000

[1]

'

'

39,779,000

[1]

17,457,000

[1]

'

'

15,839,000

[1]

15,312,000

[1]

'

'

'

'

'

'

'

'

'

'

Face amount

'

'

'

'

'

'

'

'

'

150,000,000

'

'

360,000,000

'

'

'

230,000,000

'

'

'

'

'

230,000,000

'

'

'

'

650,000,000

'

Interest rate

'

'

'

'

'

'

'

'

'

5.50%

5.50%

'

6.00%

6.00%

6.00%

'

3.25%

3.25%

'

3.25%

5.00%

'

5.00%

'

'

'

'

10.00%

10.00%

Proceeds from related party debt

'

'

'

'

'

'

'

'

'

'

'

20,500,000

6,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Underwriter option to purchase additional principal, face amount

'

'

'

'

'

'

'

'

'

22,500,000

'

'

54,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from issuance of long-term debt

'

'

'

'

'

'

'

'

'

165,600,000

'

'

395,700,000

'

'

'

223,100,000

'

'

'

'

'

'

'

'

'

'

635,400,000

'

Convertible conversion ratio

'

'

'

'

'

'

'

'

'

138.8889

'

'

83.333

'

'

'

14.0056

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debt instrument, conversion price

'

'

'

'

'

'

'

'

'

$7.20

'

'

$12

'

'

'

$71.40

'

'

'

'

'

$13.80

'

'

'

'

'

'

Percentage above which the company has the right to redeem the notes

'

'

'

'

'

'

'

'

'

130.00%

'

'

130.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Threshold trading days

'

'

'

'

'

'

'

'

'

20

'

'

20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Threshold consecutive trading days

'

'

'

'

'

'

'

'

'

'30 days

'

'

'30 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Redemption price of principal amount

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchased face amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

217,900,000

'

'

'

'

'

'

'

Repurchase amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,000

8,000,000

'

'

'

'

'

'

'

Conversion face amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

300,000

9,400,000

'

'

'

'

'

'

'

Stock issued during the period, shares

51,750,000

37,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

13,800,000

'

'

'

'

'

'

'

99,723

'

'

'

'

'

Conversion of exchangeable shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,471

'

'

'

'

'

Redemption percentage of principal amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

105.00%

'

'

'

Redeemable principal from proceeds from equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

35.00%

'

'

Redeemable percentage of principal from proceed from equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

110.00%

'

'

Fair market value of assets excluded from security interest, maximum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,000,000

'

Cash collateral excluded from security interest, maximum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

105.00%

'

Voting stock of foreign subsidiaries excluded from security interest, minimum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

65.00%

'

Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total capital leases payments due

'

'

50,200,000

8,100,000

51,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due in 2014

'

'

7,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due in 2015

'

'

7,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due in 2016

'

'

7,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due in 2017

'

'

6,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due in 2018

'

'

5,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due thereafter

'

'

17,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Executory costs

'

'

1,700,000

'

2,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Imputed interest

'

'

26,900,000

700,000

33,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of capital leases

'

'

'

7

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Term of each capital lease agreement

'

'

'

'48 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term purchase commitment, monthly purchase amount

'

'

$400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Purchase Commitment, Period (in years)

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Interest cost includes the coupon interest, accretion of the initial equity component of the convertible notes described below (3.25% - $36,227; 6.00% - $68,695; and 5.50% - $21,815), accretion of the underwriting discounts and amortization of the issuance costs allocated to the liability component.

Debt_and_Capital_Lease_Obligat3

Debt and Capital Lease Obligations (Schedule Of Long-Term Debt Instruments) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Total debt, Current	$14,128	$39,252
Capital lease obligations, Current	2,234	352
Total debt and capital lease obligations, Current	16,362	39,604
Total debt, Non-Current	1,344,561	1,173,669
Capital lease obligations, Non-Current	19,355	15,163
Total debt and capital lease obligations, Non-Current	1,363,916	1,188,832
Convertible Debt | 3.25% Convertible Notes	'	'
Debt Instrument [Line Items]	'	'
Total debt, Current	0	0
Total debt, Non-Current	207,028	198,689
Convertible Debt | 6.00% Convertible Notes	'	'
Debt Instrument [Line Items]	'	'
Total debt, Current	0	0
Total debt, Non-Current	346,708	331,977
Convertible Debt | 5.50% Convertible Senior Notes due 2018	'	'
Debt Instrument [Line Items]	'	'
Total debt, Current	0	0
Total debt, Non-Current	148,198	0
Convertible Subordinated Debt | 5.00% Debentures, net of discount	'	'
Debt Instrument [Line Items]	'	'
Total debt, Current	0	0
Total debt, Non-Current	2,493	2,774
Senior Notes | 10% Senior Securied Notes, net of discount, due June 2020	'	'
Debt Instrument [Line Items]	'	'
Total debt, Current	0	0
Total debt, Non-Current	637,435	636,111
Molycorp Canada and Molycorp Silmet | Notes Payable to Banks | Bank Loans Due September 2017	'	'
Debt Instrument [Line Items]	'	'
Total debt, Current	14,128	39,252
Total debt, Non-Current	$2,699	$4,118

Debt_and_Capital_Lease_Obligat4

Debt and Capital Lease Obligations (Schedule Of Long-Term Debt Conversions) (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 15, 2011

Dec. 31, 2013

Dec. 31, 2012

Aug. 22, 2012

Dec. 31, 2013

Jan. 30, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Senior Notes

Senior Notes

Additional Paid-In Capital

Additional Paid-In Capital

Additional Paid-In Capital

3.25% Convertible Notes

3.25% Convertible Notes

3.25% Convertible Notes

3.25% Convertible Notes

6.00% Convertible Notes

6.00% Convertible Notes

6.00% Convertible Notes

5.50% Convertible Senior Notes due 2018

5.50% Convertible Senior Notes due 2018

5.50% Convertible Senior Notes due 2018

10% Senior Securied Notes, net of discount, due June 2020

10% Senior Securied Notes, net of discount, due June 2020

Convertible Debt

Convertible Debt

Convertible Debt

3.25% Convertible Notes

6.00% Convertible Notes

5.50% Convertible Senior Notes due 2018

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amount

'

'

'

$230,000

$230,000

'

'

$414,000

$414,000

'

$172,500

'

'

$650,000

$650,000

'

'

'

Unamortized debt discount

'

'

'

-22,972

-31,311

'

'

-67,292

-82,023

'

-24,302

'

'

-12,565

-13,889

'

'

'

Net carrying amount

1,344,561

1,173,669

'

207,028

198,689

'

'

346,708

331,977

'

148,198

'

0

637,435

636,111

'

'

'

Equity component

21,815

68,695

36,227

'

'

'

'

'

'

'

'

'

'

'

'

36,227

68,695

21,815

Interest cost

'

'

'

$15,839

[1]

$15,312

[1]

'

'

$39,779

[1]

$17,457

[1]

'

$13,107

[1]

'

'

$66,323

[1]

$40,070

[1]

'

'

'

Interest rate

'

'

'

3.25%

'

3.25%

3.25%

6.00%

6.00%

6.00%

5.50%

5.50%

'

'

'

'

'

'

[1]

Interest cost includes the coupon interest, accretion of the initial equity component of the convertible notes described below (3.25% - $36,227; 6.00% - $68,695; and 5.50% - $21,815), accretion of the underwriting discounts and amortization of the issuance costs allocated to the liability component.

Income_Taxes_Narrative_Details

Income Taxes Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Impairment of goodwill and other long-lived assets	$27,200,000	'	'
Deferred tax liabilities, net	85,416,000	150,886,000	'
Valuation allowance	107,358,000	20,631,000	'
Decreases in uncertain tax positions resulting from acquisition	5,200,000	'	'
Effective income tax rate	16.40%	10.30%	19.50%
Foreign subsidiary earnings and withholding taxes	14,804,000	32,637,000	'
Deferred income tax expense due to elimination of intercompany balances and transactions	1,000,000	'	'
Income tax payable due to elimination of intercompany balances and transactions	1,000,000	'	'
Federal tax rate	35.00%	35.00%	35.00%
Tax credit carryforward	8,400,000	'	'
Statute of limitations closures	416,000	1,406,000	0
Settlements	4,737,000	13,740,000	0
Changes related to uncertain tax positions	-5,153,000	-14,176,000	0
IRS	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Operating Loss Carryforwards	290,700,000	'	'
State	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Operating Loss Carryforwards	270,100,000	'	'
Foreign Tax Authority	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Operating Loss Carryforwards	165,100,000	'	'
Expiring in 2023	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Operating Loss Carryforwards	28,600,000	'	'
Expiring between 2028 and 2032	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Tax credit carryforward	6,000,000	'	'
Expiring in 2031	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Tax credit carryforward	6,200,000	'	'
Indefinite Carryforward	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]	'	'	'
Tax credit carryforward	$2,200,000	'	'

Schedule_of_Components_of_Inco

Schedule of Components of Income Tax Expense (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current	'	'	'
Federal	($2,581)	($22,418)	$18,721
Foreign	-1,018	8,994	0
State	792	-4,197	6,952
Total current	-2,807	-17,621	25,673
Deferred	'	'	'
Federal	-43,479	-20,786	3,687
Foreign	-16,517	-11,777	0
State	-8,140	-3,891	-784
Total deferred	-68,136	-36,454	2,903
Total tax provision	($70,943)	($54,075)	$28,576

Schedule_of_Income_before_Inco

Schedule of Income before Income Tax, Domestic and Foreign (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Income Tax Disclosure [Abstract]

'

'

'

'

'

'

'

'

'

'

'

United States

'

'

'

'

'

'

'

'

($286,818)

($161,129)

$141,801

Foreign

'

'

'

'

'

'

'

'

-145,458

-363,062

5,109

(Loss) income from continuing operations before income taxes and equity earnings

($228,592)

[1]

($76,181)

[1]

($70,254)

[1]

($57,249)

[1]

($381,902)

[2]

($42,984)

[2]

($93,871)

[2]

($5,434)

[2]

($432,276)

($524,191)

$146,910

[1]

Includes the following impairment charges in the fourth quarter: goodwill, $11.0 million; rare earths quotas, $67.2 million; patents, $10.2 million; exploration rights, $16.2 million; cost-method investments $9.4 million and long-lived tangible assets, $16.3 million.

[2]

The sum of the quarterly income (loss) per share may be different than the per share amount for the year as the calculation for each quarter is based on the weighted average shares outstanding for that period.

Schedule_of_Effective_Income_T

Schedule of Effective Income Tax Reconciliation (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Federal tax computed at the statutory rate	($151,297)	($184,075)	$51,419
State taxes, net of federal benefit	-10,329	-5,970	5,255
Change in valuation allowance	85,881	19,515	-22,730
Impairment of goodwill and other long-lived assets	7,458	103,563	0
Acquisition costs	0	4,945	0
Changes related to uncertain tax positions	-5,153	-14,176	0
Federal and State tax credits	2,946	-6,817	-2,627
Domestic production activities deduction	0	2,493	-2,493
Foreign income tax rate differential	24,315	18,682	-1,735
Foreign translation adjustments	-7,744	0	0
Change in applicable law	-5,884	0	0
Other items, net	-11,136	7,765	1,487
Total tax provision	($70,943)	($54,075)	$28,576

Schedule_of_Deferred_Tax_Asset

Schedule of Deferred Tax Assets and Liabilities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current:	'	'
Inventory	$2,570	$11,951
Other	2,605	2,468
Total current	5,175	14,419
Non-current:	'	'
Asset retirement obligation	0	165
Mineral resources	16,886	16,780
Property, plant and equipment and intangible assets	21,044	13,435
Stock compensation	1,964	1,724
Net operating losses	144,366	56,156
Research and energy tax credits	6,233	10,473
Alternative Minimum Tax Credit	2,216	1,611
Unrealized foreign exchange	5,664	0
Investments	3,120	0
Other	4,107	823
Total non-current	205,600	101,167
Current	'	'
Inventory	1,312	3,395
Other	1,423	541
Total current	2,735	3,936
Non-current:	'	'
Asset retirement obligation	1,190	0
Foreign subsidiary earnings and withholding taxes	14,804	32,637
Property, plant and equipment and intangible assets	91,585	137,010
Section 174 costs	33,942	24,814
Convertible debt (Notes)	44,275	40,478
Other	302	6,966
Total non-current	186,098	241,905
Net deferred taxes, before valuation allowance	21,942	-130,255
Valuation allowance	-107,358	-20,631
Total deferred tax	($85,416)	($150,886)

Schedule_of_Income_Tax_Conting

Schedule of Income Tax Contingencies (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]	'	'	'
Balance, beginning of year	$6,219	$519	$0
Tax position related to current year:	'	'	'
Additions	0	4,737	519
Tax positions related to prior years:	'	'	'
Additions	0	16,109	0
Settlements	-4,737	-13,740	0
Statute of limitations closures	-416	-1,406	0
Balance, end of year	$1,066	$6,219	$519

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)

0 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

7 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

12 Months Ended

24 Months Ended

0 Months Ended

12 Months Ended

Oct. 21, 2013

Jan. 30, 2013

Feb. 16, 2011

Aug. 31, 2012

Jun. 30, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2012

Jun. 11, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Aug. 22, 2012

Dec. 31, 2013

Jun. 12, 2012

Aug. 31, 2012

Dec. 31, 2012

Jan. 30, 2013

Aug. 23, 2012

Dec. 31, 2013

Dec. 31, 2013

Aug. 31, 2012

Aug. 31, 2012

Feb. 16, 2011

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2013

Feb. 16, 2011

Feb. 16, 2011

Jan. 30, 2013

Mar. 08, 2012

Dec. 31, 2012

Dec. 31, 2012

Common Stock

Common Stock

MCP Exchangeco Inc.

Molycorp

Exploration rights

Exploration rights

Exploration rights

6.00% Convertible Notes

6.00% Convertible Notes

6.00% Convertible Notes

5.00% Debentures, net of discount

5.00% Debentures, net of discount

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Series A Mandatory Convertible Preferred Stock

Series A Mandatory Convertible Preferred Stock

Series A Mandatory Convertible Preferred Stock

Series A Mandatory Convertible Preferred Stock

Series A Mandatory Convertible Preferred Stock

Series A Mandatory Convertible Preferred Stock

Officers, Directors and Other Related Parties

Molymet

Molymet

Molymet

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Subordinated Debt

Convertible Subordinated Debt

MCP Exchangeco Inc.

Molycorp

6.00% Convertible Notes

5.00% Debentures, net of discount

Minimum

Maximum

Common Stock

Convertible Debt

Convertible Subordinated Debt

Stockholders' Equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued during the period, shares

51,750,000

37,500,000

'

'

'

'

'

'

'

51,750,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,800,000

99,723

'

'

'

'

'

'

'

12,500,000

'

12,500,000

Shares issued during period, underwriters option to purchase

6,750,000

5,625,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Offering price per share, underwriters

$5

$6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Underwriter fees

5.00%

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares purchased to related parties

14,034,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,016,666

'

'

'

Net proceeds from sale of common stock

$247,500,000

$248,100,000

'

$132,100,000

'

'

$495,717,000

$132,130,000

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Offering price per share (in dollars per share)

'

$6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

6.00%

6.00%

5.00%

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Own-share Lending Arrangement, Shares, Offered in Registered Public Offering, Price Per Share

'

7,666,666

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of borrowed shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,666,666

13,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Offered in registered public offering (in dollars per share)

'

$6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment at cost

'

'

'

'

'

1,589,235,000

1,865,552,000

1,589,235,000

'

'

'

'

'

0

16,166,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of shares for investment in mining property

'

'

'

'

'

'

'

'

'

'

788,410

'

'

'

788,410

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of stock, price per share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10.15

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments to acquire exploration rights

'

'

'

'

'

8,200,000

0

8,167,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Tangible Asset Impairment Charges

'

'

'

'

'

'

16,300,000

5,900,000

'

'

'

'

'

16,200,000

'

16,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share price (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Underwriting discounts and commissions

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Flat fee paid to underwriters

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Primary shares purchased by insiders

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,090,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Underwriter option to purchase additional shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

270,000

'

'

'

'

'

'

'

'

'

Common stock issued to acquire the entity (in shares)

'

'

'

'

'

'

'

'

'

'

'

507,203

13,545,426

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of Molycorp common stock and Exchangeable Shares issued

'

'

'

'

284,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exchangeable shares converted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

340,196

'

'

358,812

102,194

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of exchangeable shares

'

'

'

'

'

'

'

'

'

18,616

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,471

'

'

'

'

'

'

'

'

'

'

Issuance of shares

'

'

'

'

'

'

247,567,000

'

'

52,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

390,100,000

390,093,000

12,000

Stock issuance costs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000

'

'

Price per share of common stock issued for investment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$31.22

'

'

Number of consecutive trading days to calculate common stock price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'20 days

'

'

Dividend rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.50%

'

'

'

'

'

'

'

'

Premium percentage added to common stock price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10.00%

'

'

Preferred stock, par value

'

'

'

'

'

'

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.00

'

'

'

'

'

'

'

'

'

Preferred stock, shares issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,800,000

'

'

'

'

'

'

'

'

'

Mandatory convertible preferred stock price per share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$100

'

'

'

'

'

'

'

'

'

Preferred shares issued upon conversion

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.6667

2

'

'

'

'

Net proceeds from sale of preferred stock

'

'

199,600,000

'

'

'

0

0

199,642,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash dividend declared (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.38

'

'

'

'

'

'

Cash dividend declared and paid

'

'

'

'

'

'

$11,385,000

$11,385,000

$9,015,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$9,000,000

$11,400,000

'

'

'

'

'

'

Earnings_per_Share_Details

Earnings per Share (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, except Share data, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2011

Jun. 15, 2011

Dec. 31, 2013

Dec. 31, 2012

Aug. 22, 2012

Dec. 31, 2013

Jan. 30, 2013

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

Convertible Debt

3.25% Convertible Notes

3.25% Convertible Notes

3.25% Convertible Notes

6.00% Convertible Notes

6.00% Convertible Notes

6.00% Convertible Notes

5.50% Convertible Senior Notes due 2018

5.50% Convertible Senior Notes due 2018

Retained Earnings Adjustments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net (loss) income attributable to Molycorp stockholders

($194,308)

($69,929)

($71,175)

($38,971)

($391,196)

($18,891)

($67,604)

($3,478)

($374,383)

($481,169)

$117,526

'

'

'

'

'

'

'

'

Dividends on Convertible Preferred Stock

'

'

'

'

'

'

'

'

-11,385

-11,385

-9,962

'

'

'

'

'

'

'

'

(Loss) income attributable to common stockholders

'

'

'

'

'

'

'

'

-385,768

-492,554

107,564

'

'

'

'

'

'

'

'

Continuing operations

'

'

'

'

'

'

'

'

-379,341

-490,817

107,564

'

'

'

'

'

'

'

'

Discontinued operations

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

Weighted average common shares outstanding—basic

'

'

'

'

'

'

'

'

174,528,717

107,064,892

83,454,221

'

'

'

'

'

'

'

'

Basic (loss) earnings per share from:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Continuing operations (in dollars per share)

'

'

'

'

'

'

'

'

($2.17)

($4.58)

$1.29

'

'

'

'

'

'

'

'

Discontinued operations (in dollars per share)

'

'

'

'

'

'

'

'

($0.04)

($0.02)

$0

'

'

'

'

'

'

'

'

Basic (in dollars per share)

($0.95)

($0.43)

($0.44)

($0.27)

($3.16)

($0.19)

($0.71)

($0.07)

($2.21)

($4.60)

$1.29

'

'

'

'

'

'

'

'

Effect of dilutive 3.25% Convertible Notes

'

'

'

'

'

'

'

'

0

0

413

'

'

'

'

'

'

'

'

Adjusted (loss) income attributable to common stockholders

'

'

'

'

'

'

'

'

-385,768

-492,554

107,977

'

'

'

'

'

'

'

'

Continuing operations

'

'

'

'

'

'

'

'

-379,341

-490,817

107,977

'

'

'

'

'

'

'

'

Discontinued operations

'

'

'

'

'

'

'

'

($6,427)

($1,737)

$0

'

'

'

'

'

'

'

'

Weighted average common shares outstanding—diluted

'

'

'

'

'

'

'

'

174,528,717

107,064,892

85,220,017

'

'

'

'

'

'

'

'

Diluted (loss) earnings per share from:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Continuing operations (in dollars per share)

'

'

'

'

'

'

'

'

($2.17)

($4.58)

$1.27

'

'

'

'

'

'

'

'

Discontinued operations (in dollars per share)

'

'

'

'

'

'

'

'

($0.04)

($0.02)

$0

'

'

'

'

'

'

'

'

Diluted (in dollars per share)

($0.95)

($0.43)

($0.44)

($0.27)

($3.16)

($0.19)

($0.71)

($0.07)

($2.21)

($4.60)

$1.27

'

'

'

'

'

'

'

'

Interest rate

'

'

'

'

'

'

'

'

'

'

'

3.25%

3.25%

3.25%

6.00%

6.00%

6.00%

5.50%

5.50%

StockBased_Compensation_Narrat

Stock-Based Compensation Narrative (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Number of shares available for grant	2,055,435	'	'
Forfeiture benefits	$1.50	$1.60	'
Weighted average remaining contractual term	'3 years 0 months 14 days	'	'
Stock-based compensation expense	5.4	3.4	4.7
Number of committed-to-be-released shares	28,436	'	'
RSUs	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Vesting period (in years)	'3 years	'	'
Matching contribution by entity (as a percent)	25.00%	'	'
PBRSUs | Minimum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Percentage of units vesting	0.00%	'	'
PBRSUs | Maximum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Percentage of units vesting	150.00%	'	'
RSAs, RSUs and PBRSUs	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Compensation cost not yet recognized	9.7	'	'
Weighted-average period for unrecognized compensation costs	'2 years 1 month 24 days	'	'
Stock Options	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Vesting period (in years)	'3 years	'	'
Option contractual term	'10 years	'	'
Employee Stock Purchase Plan	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Number of shares available for grant	'	300,000	'
Stock-based compensation expense	$0.10	'	'

Allocation_of_Recognized_Perio

Allocation of Recognized Period Costs (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'	'
Stock-based compensation expense	$5.40	$3.40	$4.70
Income tax benefit	$0	$0.90	$0.80

Activity_Related_to_Restricted

Activity Related to Restricted Stock-based Awards (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Restricted Stock	'
Number of Shares	'
Unvested at the beginning of the period (in shares)	39,974
Granted (in shares)	0
Forfeited (in shares)	-8,148
Vested (in shares)	-25,500
Unvested at the end of the period (in shares)	6,326
Weighted Average Grant-Date Price	'
Unvested shares at the beginning of the period (in dollars per share)	$40.09
Granted (in dollars per share)	$0
Forfeited (in dollars per share)	$39.77
Vested (in dollars per share)	$36.51
Unvested shares at the end of the period (in dollars per share)	$55.05
RSUs	'
Number of Shares	'
Unvested at the beginning of the period (in shares)	181,602
Granted (in shares)	1,005,757
Forfeited (in shares)	-85,119
Vested (in shares)	-25,855	[1]
Unvested at the end of the period (in shares)	1,076,385
Weighted Average Grant-Date Price	'
Unvested shares at the beginning of the period (in dollars per share)	$32.15
Granted (in dollars per share)	$7.02
Forfeited (in dollars per share)	$27.15
Vested (in dollars per share)	$6.89	[1]
Unvested shares at the end of the period (in dollars per share)	$9.81
PBRSUs	'
Number of Shares	'
Unvested at the beginning of the period (in shares)	29,302
Granted (in shares)	897,515
Forfeited (in shares)	-69,546
Vested (in shares)	-159,474
Unvested at the end of the period (in shares)	697,797
Weighted Average Grant-Date Price	'
Unvested shares at the beginning of the period (in dollars per share)	$30.33
Granted (in dollars per share)	$6.84
Forfeited (in dollars per share)	$11
Vested (in dollars per share)	$6.64
Unvested shares at the end of the period (in dollars per share)	$7.45
[1]	a) deferral and conversion of a portion of fees payable to certain non-employee directors of the Company; b) deferral and conversion of a portion of the 2012 annual cash bonuses paid to certain executive officers and other employees of the Company; and c) RSUs with an accelerated vesting period that were granted to some employees of Molycorp Canada on the acquisition date.

Restricted_Stock_Additional_In

Restricted Stock Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
PBRSUs	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted average grant-date fair value of shares granted	$6.10	$1.40	'
Total fair value of shares vested	1.1	'	'
RSUs	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted average grant-date fair value of shares granted	7.1	5.5	4.5
Total intrinsic value of share units converted	0.2	0.4	0.1
Total fair value of shares vested	0.2	0.8	0.1
Restricted Stock	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted average grant-date fair value of shares granted	'	'	$0.60

Valuation_Assumptions_Details

Valuation Assumptions (Details) (Stock Options)	12 Months Ended
	Dec. 31, 2011
Stock Options	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Risk-free interest rate	2.21%
Expected term (in years)	'6 years
Volatility	60.10%
Expected dividend yield	0.00%

Stock_Option_Activity_Details

Stock Option Activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Number of Shares	'
Outstanding at beginning of year (in shares)	35,624
Granted (in shares)	0
Exercised (in shares)	0
Forfeited and expired (in shares)	-9,008
Outstanding at end of year (in shares)	26,616
Options exercisable at year-end (in shares)	17,744
Weighted Average Exercise Price	'
Outstanding at beginning of year (in dollars per share)	$48.87
Granted (in dollars per share)	$0
Exercised (in dollars per share)	$0
Forfeited and expired (in dollars per share)	$48.87
Outstanding at end of year (in dollars per share)	$48.87
Options exercisable at year-end (in dollars per share)	$48.87

Stock_Option_Additional_Inform

Stock Option Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'	'
Weighted average grant-date fair value of options granted	'	'	$1.50
Total fair value of options vested	$0.50	$0.30	'

Commitments_and_Contingencies_1

Commitments and Contingencies Operating Leases (Details) (Office space, trailers and certain equipment, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2010
Office space, trailers and certain equipment	'	'	'
Remaining annual minimum payments under operating leases	'	'	'
Operating lease obligations, total minimum payments	$6,283,000	'	'
Operating lease obligations, Less Than 1 Year	2,583,000	'	'
Operating lease obligations, 1 -3 Years	2,263,000	'	'
Operating lease obligations, 4 - 5 Years	442,000	'	'
Operating lease obligations, More Than 5 Years	995,000	'	'
Operating leases rent expense net	$4,000,000	$4,100,000	$700,000

Commitments_and_Contingencies_2

Commitments and Contingencies Purchase Commitments (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'
Purchase obligations and other commitment, Total	$238,945
Purchase obligations and other commitment, Less Than 1 Year	216,249
Purchase obligations and other commitment, 1 - 3 Years	12,813
Purchase obligations and other commitment, 4 - 5 Years	6,239
Purchase obligations and other commitment, More Than Five Years	$3,644

Commitments_and_Contingencies_3

Commitments and Contingencies Narrative (Details) (USD $)	Dec. 31, 2013	Aug. 31, 2012	Jul. 31, 2012	Aug. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
In Millions, unless otherwise specified	employee	Consolidated Class Action	Consolidated Class Action	Purported Class Action	Workforce	Workforce
		lawsuit	claim	lawsuit	Employees covered by collective bargaining agreement under facility	Employees covered by collective bargaining agreement under facility
					Molycorp Mountain Pass facility	Molycorp Silmet
					employee	employee
Plant Modernization and Expansion Commitments	'	'	'	'	'	'
Number of employees	2,600	'	'	'	237	171
Concentration risk (as a percent)	'	'	'	'	61.00%	30.00%
Surety bonds placed to secure the closure and reclamation obligations	$28.80	'	'	'	'	'
Number of claims	'	'	18	'	'	'
Number of stockholder derivative lawsuits	'	2	'	2	'	'

Concentrations_Details

Concentrations (Details) (USD $)

3 Months Ended

12 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

7 Months Ended

12 Months Ended

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Daido Electronics

Product Concentration

Product Concentration

Accounts Receivable

Resources

Magnetic Materials and Alloys

Lanthanum products

Cerium products

Cerium products

Cerium products

Neodymium and Praseodymium products

Neo Powders

Neo Powders

Neo Powders

Neo Powders

NdFeB Alloys

Hitachi Metals Ltd.

Santoku

Two Major Customers

Resources

Product Concentration

Product Concentration

Resources

Resources

Daido Electronics

Daido Electronics

Magnetic Materials and Alloys

Magnetic Materials and Alloys

Magnetic Materials and Alloys

Molycorp Tolleson

Molycorp Tolleson

Customers Concentration

Product Concentration

Chemicals and Oxides

Chemicals and Oxides

Product Concentration

Product Concentration

Product Concentration

Product Concentration

Customers Concentration

Customers Concentration

customer

Concentrations

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Entity-wide revenue, major customers

'

'

'

'

'

'

'

'

'

'

'

'

23.00%

12.00%

26.00%

'

'

23.00%

9.00%

15.00%

11.00%

26.00%

'

'

41.00%

25.00%

11.00%

Sales, net of intercompany transactions

$123,814,000

$149,066,000

$136,112,000

$145,398,000

$133,611,000

$205,205,000

$104,410,000

$84,470,000

$554,390,000

$527,696,000

$396,831,000

'

$92,200,000

$48,800,000

'

$59,661,000

$252,713,000

'

'

'

'

'

'

'

'

'

'

Number of major customers

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

Sales to related party

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

32,900,000

56,500,000

'

'

'

Related party receivables

'

'

'

'

'

'

'

'

'

'

'

$7,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

RelatedParty_Transactions_Deta

Related-Party Transactions (Details) (USD $)	7 Months Ended	12 Months Ended	7 Months Ended	12 Months Ended	7 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended	5 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2013
	TMT	TMT	TMT	TMT	Keli	Keli	Ingal Stade	Ingal Stade	Plansee
	Neo Powders	Neo Powders	Compounds	Compounds	Metals	Metals	Gallium Metal	Gallium Metal	Recycling Activities
Related Party Transactions	'	'	'	'	'	'	'	'	'
Sales to related party	$1.60	$4.50	'	'	'	'	'	'	$0.30
Purchases made from related party	'	'	$2.80	$2.10	$32.60	$61.30	$3.30	$4.90	'

Net_Change_in_Operating_Assets2

Net Change in Operating Assets and Liabilities (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Decrease (increase) in operating assets:	'	'	'
Accounts receivable	'	$124,983	($52,805)
Inventory	'	-46,126	-64,543
Prepaid expenses and other assets	'	33,520	-6,363
Increase (decrease) in operating liabilities:	'	'	'
Accounts payable	'	-34,972	16,233
Income tax payable	'	-40,263	-17,832
Interest payable	'	-40,792	0
Asset retirement obligation	'	-1,467	-1,030
Accrued expenses	'	-54,763	6,151
Net change in operating assets and liabilities	($64,719)	($59,880)	($120,189)

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net cash paid for:	'	'	'
Income taxes	($13,429)	$178	$43,505
Interest, net of capitalized interest	32,833	8,942	273
Non-cash financing activities and investing activities:	'	'	'
Change in accrued capital expenditures	58,673	52,189	112,606
Conversion of debt securities to equity securities	18	4,527	0
Acquisition of exploration rights	0	8,000	0
Debt assumed from business acquisitions	0	40,691	3,184
Issuance of common stock for business acquisitions	0	284,100	72,700
Fixed assets additions under capital lease	$7,370	$15,658	$0

Derivative_Instruments_Narrati

Derivative Instruments Narrative (Details)	Mar. 28, 2012	Dec. 31, 2013	Dec. 31, 2012	Jun. 15, 2011	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	CAD	Interest Expense	Interest Expense	Other Expense	Derivative Liability	Derivative Liability
		USD ($)	USD ($)	USD ($)	USD ($)	USD ($)
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'	'	'	'	'
Fair value of put option	'	'	'	'	$6.10	$7.80
Unrealized gain on change in put option fair value	'	1.7	-1.2	'	'	'
Notional amount of derivatives	870	'	'	'	'	'
Realized loss on settlement of derivative forward contracts	'	'	'	$37.60	'	'

Fair_Value_Put_Level_3_Inputs_

Fair Value Put Level 3 Inputs (Details) (Derivative Liability, Income Approach Valuation Technique, Level 3, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Derivative Liability | Income Approach Valuation Technique | Level 3	'
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]	'
Equity-risk premium	6.50%
Risk premium	12.90%
Size premium	3.80%
Growth rate	1.00%
Equity-risk premium, Effect of 1% increase	($0.60)	[1]
Risk premium, Effect of 1% increase	-0.2	[1]
Size premium, Effect of 1% increase	-0.3	[1]
Growth rate, Effect of 1% increase	0.2	[1]
Equity-risk premium, Effect of 1% decrease	0.7	[1]
Risk premium, Effect of 1% decrease	0.3	[1]
Size premium, Effect of 1% decrease	0.4	[1]
Growth rate, Effect of 1% decrease	($0.20)	[1]
[1]	Assuming all other inputs are unchanged.

Employee_Benefit_Plans_Narrati

Employee Benefit Plans (Narrative) (Details) (USD $)

3 Months Ended

7 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

Mar. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jul. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Napanee Facility

Employee Severance

Pension Plan

Pension Plan

Pension Plan

Pension Plan

Pension Plan and Other Postretirement Benefit Plan

Debt Securities

Debt Securities

Equity Securities

Interest-bearing Deposits

Molycorp Canada

Level 2

Anderson, Indiana Manufacturing Facility

participant

Defined Benefit Plan Disclosure [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Company matching contribution as a percentage of the first 3.0% compensation contributed by each eligible employee

'

'

100.00%

'

'

'

'

'

'

'

'

'

Percentage of each employee's compensation eligible for Company match of 100% in defined contribution plan

'

'

3.00%

'

'

'

'

'

'

'

'

'

Company matching contribution as a percentage of the next 2.0% of compensation contributed by each eligible employee

'

'

50.00%

'

'

'

'

'

'

'

'

'

Percentage of each employee's compensation eligible for Company match of 50% in defined contribution plan

'

'

2.00%

'

'

'

'

'

'

'

'

'

Safe harbor matching contribution vesting percentage

'

'

100.00%

'

'

'

'

'

'

'

'

'

Vesting percentage of discretionary matching contribution after 3 years of service

'

'

100.00%

'

'

'

'

'

'

'

'

'

Period of service after which employees vest in Company contributions

'

'

'3 years

'

'

'

'

'

'

'

'

'

Expenses related to defined contribution plan

'

'

$2,900,000

$1,600,000

$1,600,000

'

'

'

'

'

'

'

Accrued expenses related to defined contribution plan

'

1,400,000

1,921,000

1,400,000

'

'

'

'

'

'

'

'

Discretionary contributions to the Management Incentive Plan (MIP) funded by the Company

'

'

500,000

400,000

300,000

'

'

'

'

'

'

'

Total accrued amount for the MIP including employee deferrals, discretionary contributions and related earnings

'

900,000

1,200,000

900,000

'

'

'

'

'

'

'

'

Accrued expense for cash portion of bonus plan

'

3,503,000

4,449,000

3,503,000

'

'

'

'

'

'

'

'

Number of participants

'

'

'

'

'

'

'

'

'

'

'

293

Benefit obligation

'

8,900,000

7,600,000

8,900,000

'

'

'

'

'

'

'

'

Fair value of plan assets

'

5,600,000

5,600,000

5,600,000

'

'

'

3,800,000

3,589,000

1,400,000

400,000

'

Funded status of plan

'

3,300,000

2,000,000

3,300,000

'

'

'

'

'

'

'

'

Net periodic benefit cost

'

100,000

300,000

'

'

'

'

'

'

'

'

'

Severance costs

2,100,000

'

'

'

'

100,000

'

'

'

'

'

'

Payments for restructuring

'

'

'

'

'

'

$1,900,000

'

'

'

'

'

Condensed_Consolidating_Balanc

Condensed Consolidating Balance Sheet (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Current assets:	'	'	'	'
Cash and cash equivalents	$314,317	$227,790	$418,855	$316,430
Trade accounts receivable, net (Note 2)	61,757	52,430	'	'
Inventory	171,783	287,376	'	'
Deferred charges	1,046	9,412	'	'
Deferred tax assets	1,456	9,789	'	'
Income tax receivable	787	25,087	'	'
Prepaid expenses and other current assets	25,921	21,794	'	'
Total current assets	577,067	633,678	'	'
Non-current assets:	'	'	'	'
Deposits	25,997	26,769	'	'
Property, plant and equipment, net	1,762,874	1,544,304	'	'
Inventory	25,329	26,096	'	'
Intangible assets, net	330,867	450,938	'	'
Investments	48,875	64,036	'	'
Deferred tax assets	109	0	'	'
Goodwill	228,750	239,742	3,432	0
Investments in consolidated subsidiaries	0	0	'	'
Intercompany accounts receivable	0	0	'	'
Other non-current assets	6,934	6,972	'	'
Total non-current assets	2,429,735	2,358,857	'	'
Total assets	3,006,802	2,992,535	1,255,125	'
Current liabilities:	'	'	'	'
Trade accounts payable	84,449	241,994	'	'
Accrued expenses	48,501	59,013	'	'
Income tax payable	1,946	15,267	'	'
Deferred tax liabilities	1,500	0	'	'
Debt and capital lease obligations	16,362	39,604	'	'
Other current liabilities	617	3,539	'	'
Total current liabilities	153,375	359,417	'	'
Non-current liabilities:	'	'	'	'
Asset retirement obligation	16,966	18,586	'	'
Deferred tax liabilities	85,481	160,675	'	'
Debt and capital lease obligations	1,363,916	1,188,832	'	'
Derivative liability	6,089	7,816	'	'
Pension liabilities	2,044	3,292	'	'
Intercompany accounts payable	0	0	'	'
Other non-current liabilities	1,869	2,659	'	'
Total non-current liabilities	1,476,365	1,381,860	'	'
Total liabilities	1,629,740	1,741,277	'	'
Stockholders’ equity:	'	'	'	'
Common stock	241	139	'	'
Preferred stock	2	2	'	'
Additional paid-in capital	2,194,405	1,691,429	'	'
Accumulated other comprehensive loss	-6,451	-9,433	'	'
Accumulated deficit	-840,474	-466,091	'	'
Total Molycorp stockholders’ equity	1,347,723	1,216,046	'	'
Noncontrolling interests	29,339	35,212	'	'
Total stockholders’ equity	1,377,062	1,251,258	845,230	446,513
Total liabilities and stockholders’ equity	3,006,802	2,992,535	'	'
Parent	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	169,145	16,560	407,446	316,430
Trade accounts receivable, net (Note 2)	0	0	'	'
Inventory	0	0	'	'
Deferred charges	0	0	'	'
Deferred tax assets	0	0	'	'
Income tax receivable	0	0	'	'
Prepaid expenses and other current assets	0	0	'	'
Total current assets	169,145	16,560	'	'
Non-current assets:	'	'	'	'
Deposits	1,754	1,752	'	'
Property, plant and equipment, net	0	0	'	'
Inventory	0	0	'	'
Intangible assets, net	0	0	'	'
Investments	0	0	'	'
Deferred tax assets	0	6,030	'	'
Goodwill	0	0	'	'
Investments in consolidated subsidiaries	532,767	883,319	'	'
Intercompany accounts receivable	2,001,583	1,539,877	'	'
Other non-current assets	0	0	'	'
Total non-current assets	2,536,104	2,430,978	'	'
Total assets	2,705,249	2,447,538	'	'
Current liabilities:	'	'	'	'
Trade accounts payable	0	0	'	'
Accrued expenses	18,158	14,872	'	'
Income tax payable	0	0	'	'
Deferred tax liabilities	0	0	'	'
Debt and capital lease obligations	0	0	'	'
Other current liabilities	0	0	'	'
Total current liabilities	18,158	14,872	'	'
Non-current liabilities:	'	'	'	'
Asset retirement obligation	0	0	'	'
Deferred tax liabilities	0	0	'	'
Debt and capital lease obligations	1,339,368	1,166,777	'	'
Derivative liability	0	0	'	'
Pension liabilities	0	0	'	'
Intercompany accounts payable	0	49,843	'	'
Other non-current liabilities	0	0	'	'
Total non-current liabilities	1,339,368	1,216,620	'	'
Total liabilities	1,357,526	1,231,492	'	'
Stockholders’ equity:	'	'	'	'
Common stock	241	139	'	'
Preferred stock	2	2	'	'
Additional paid-in capital	2,194,405	1,691,429	'	'
Accumulated other comprehensive loss	-6,451	-9,433	'	'
Accumulated deficit	-840,474	-466,091	'	'
Total Molycorp stockholders’ equity	1,347,723	1,216,046	'	'
Noncontrolling interests	0	0	'	'
Total stockholders’ equity	1,347,723	1,216,046	'	'
Total liabilities and stockholders’ equity	2,705,249	2,447,538	'	'
Guarantor Subsidiaries	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	6,467	18,020	10,758	0
Trade accounts receivable, net (Note 2)	4,990	7,738	'	'
Inventory	32,307	49,416	'	'
Deferred charges	0	2,203	'	'
Deferred tax assets	0	0	'	'
Income tax receivable	0	25,087	'	'
Prepaid expenses and other current assets	15,833	9,085	'	'
Total current assets	59,597	111,549	'	'
Non-current assets:	'	'	'	'
Deposits	24,243	24,862	'	'
Property, plant and equipment, net	1,620,851	1,377,147	'	'
Inventory	25,329	26,096	'	'
Intangible assets, net	442	508	'	'
Investments	34,134	45,241	'	'
Deferred tax assets	0	0	'	'
Goodwill	0	0	'	'
Investments in consolidated subsidiaries	121,849	97,960	'	'
Intercompany accounts receivable	0	207,035	'	'
Other non-current assets	771	885	'	'
Total non-current assets	1,827,619	1,779,734	'	'
Total assets	1,887,216	1,891,283	'	'
Current liabilities:	'	'	'	'
Trade accounts payable	49,702	191,769	'	'
Accrued expenses	13,782	10,087	'	'
Income tax payable	0	0	'	'
Deferred tax liabilities	0	1,942	'	'
Debt and capital lease obligations	2,234	352	'	'
Other current liabilities	617	3,539	'	'
Total current liabilities	66,335	207,689	'	'
Non-current liabilities:	'	'	'	'
Asset retirement obligation	16,966	18,586	'	'
Deferred tax liabilities	0	23,130	'	'
Debt and capital lease obligations	19,355	15,163	'	'
Derivative liability	0	0	'	'
Pension liabilities	0	0	'	'
Intercompany accounts payable	1,999,562	1,577,363	'	'
Other non-current liabilities	1,393	1,102	'	'
Total non-current liabilities	2,037,276	1,635,344	'	'
Total liabilities	2,103,611	1,843,033	'	'
Stockholders’ equity:	'	'	'	'
Common stock	0	0	'	'
Preferred stock	0	0	'	'
Additional paid-in capital	149,857	149,857	'	'
Accumulated other comprehensive loss	0	0	'	'
Accumulated deficit	-366,252	-101,607	'	'
Total Molycorp stockholders’ equity	-216,395	48,250	'	'
Noncontrolling interests	0	0	'	'
Total stockholders’ equity	-216,395	48,250	'	'
Total liabilities and stockholders’ equity	1,887,216	1,891,283	'	'
Non-Guarantor Subsidiaries	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	138,705	193,210	651	0
Trade accounts receivable, net (Note 2)	56,767	44,692	'	'
Inventory	139,476	237,960	'	'
Deferred charges	1,046	7,209	'	'
Deferred tax assets	1,456	11,731	'	'
Income tax receivable	787	0	'	'
Prepaid expenses and other current assets	10,088	12,709	'	'
Total current assets	348,325	507,511	'	'
Non-current assets:	'	'	'	'
Deposits	0	155	'	'
Property, plant and equipment, net	142,023	167,157	'	'
Inventory	0	0	'	'
Intangible assets, net	330,425	450,430	'	'
Investments	14,741	18,795	'	'
Deferred tax assets	109	0	'	'
Goodwill	228,750	239,742	'	'
Investments in consolidated subsidiaries	0	0	'	'
Intercompany accounts receivable	0	794	'	'
Other non-current assets	6,163	6,087	'	'
Total non-current assets	722,211	883,160	'	'
Total assets	1,070,536	1,390,671	'	'
Current liabilities:	'	'	'	'
Trade accounts payable	34,747	50,225	'	'
Accrued expenses	16,561	34,054	'	'
Income tax payable	1,946	15,267	'	'
Deferred tax liabilities	1,500	0	'	'
Debt and capital lease obligations	14,128	39,252	'	'
Other current liabilities	0	0	'	'
Total current liabilities	68,882	138,798	'	'
Non-current liabilities:	'	'	'	'
Asset retirement obligation	0	0	'	'
Deferred tax liabilities	85,481	143,575	'	'
Debt and capital lease obligations	5,193	6,892	'	'
Derivative liability	6,089	7,816	'	'
Pension liabilities	2,044	3,292	'	'
Intercompany accounts payable	2,021	120,500	'	'
Other non-current liabilities	476	1,557	'	'
Total non-current liabilities	101,304	283,632	'	'
Total liabilities	170,186	422,430	'	'
Stockholders’ equity:	'	'	'	'
Common stock	0	0	'	'
Preferred stock	0	0	'	'
Additional paid-in capital	1,315,426	1,283,863	'	'
Accumulated other comprehensive loss	-6,451	-9,433	'	'
Accumulated deficit	-437,964	-341,401	'	'
Total Molycorp stockholders’ equity	871,011	933,029	'	'
Noncontrolling interests	29,339	35,212	'	'
Total stockholders’ equity	900,350	968,241	'	'
Total liabilities and stockholders’ equity	1,070,536	1,390,671	'	'
Eliminations	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	0	0	0	0
Trade accounts receivable, net (Note 2)	0	0	'	'
Inventory	0	0	'	'
Deferred charges	0	0	'	'
Deferred tax assets	0	-1,942	'	'
Income tax receivable	0	0	'	'
Prepaid expenses and other current assets	0	0	'	'
Total current assets	0	-1,942	'	'
Non-current assets:	'	'	'	'
Deposits	0	0	'	'
Property, plant and equipment, net	0	0	'	'
Inventory	0	0	'	'
Intangible assets, net	0	0	'	'
Investments	0	'	'	'
Deferred tax assets	0	-6,030	'	'
Goodwill	0	0	'	'
Investments in consolidated subsidiaries	-654,616	-981,279	'	'
Intercompany accounts receivable	-2,001,583	-1,747,706	'	'
Other non-current assets	0	0	'	'
Total non-current assets	-2,656,199	-2,735,015	'	'
Total assets	-2,656,199	-2,736,957	'	'
Current liabilities:	'	'	'	'
Trade accounts payable	0	0	'	'
Accrued expenses	0	0	'	'
Income tax payable	0	0	'	'
Deferred tax liabilities	0	-1,942	'	'
Debt and capital lease obligations	0	0	'	'
Other current liabilities	0	0	'	'
Total current liabilities	0	-1,942	'	'
Non-current liabilities:	'	'	'	'
Asset retirement obligation	0	0	'	'
Deferred tax liabilities	0	-6,030	'	'
Debt and capital lease obligations	0	0	'	'
Derivative liability	0	0	'	'
Pension liabilities	0	0	'	'
Intercompany accounts payable	-2,001,583	-1,747,706	'	'
Other non-current liabilities	0	0	'	'
Total non-current liabilities	-2,001,583	-1,753,736	'	'
Total liabilities	-2,001,583	-1,755,678	'	'
Stockholders’ equity:	'	'	'	'
Common stock	0	0	'	'
Preferred stock	0	0	'	'
Additional paid-in capital	-1,465,283	-1,433,720	'	'
Accumulated other comprehensive loss	6,451	9,433	'	'
Accumulated deficit	804,216	443,008	'	'
Total Molycorp stockholders’ equity	-654,616	-981,279	'	'
Noncontrolling interests	0	0	'	'
Total stockholders’ equity	-654,616	-981,279	'	'
Total liabilities and stockholders’ equity	($2,656,199)	($2,736,957)	'	'

Condensed_Consolidating_Statem

Condensed Consolidating Statement of Operations and Comprehensive Income (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

$123,814

$149,066

$136,112

$145,398

$133,611

$205,205

$104,410

$84,470

$554,390

$527,696

$396,831

Costs of sales:

'

'

'

'

'

'

'

'

'

'

'

Costs excluding depreciation and amortization

'

'

'

'

'

'

'

'

-553,831

-478,253

-164,351

Depreciation and amortization

'

'

'

'

'

'

'

'

-67,727

-30,621

-13,539

Gross (loss) profit

-27,049

-17,778

-18,036

-4,305

-19,703

11,494

-3,996

31,027

-67,168

18,822

218,941

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Selling, general and administrative

'

'

'

'

'

'

'

'

-107,169

-113,437

-50,757

Corporate development

'

'

'

'

'

'

'

'

-247

-19,796

-5,912

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-38,037

-22,187

-1,688

Research and development

'

'

'

'

'

'

'

'

-23,172

-27,796

-7,718

Impairment of goodwill and other long-lived assets

'

'

'

'

'

'

'

'

-120,898

-301,755

0

Operating (loss) income

'

'

'

'

'

'

'

'

-356,691

[1]

-466,149

[1]

152,866

Other (expense) income:

'

'

'

'

'

'

'

'

'

'

'

Other income (expense)

'

'

'

'

'

'

'

'

-7,525

-38,798

-153

Foreign exchange gain (loss), net

'

'

'

'

'

'

'

'

-376

2,872

-5,415

Interest expense, net of capitalized interest

'

'

'

'

'

'

'

'

-67,684

-22,116

-388

Interest income (expense) from intercompany notes

'

'

'

'

'

'

'

'

0

0

0

Equity earnings from consolidated subsidiaries

'

'

'

'

'

'

'

'

0

0

0

Total other expense

'

'

'

'

'

'

'

'

-75,585

-58,042

-5,956

(Loss) income from continuing operations before income taxes and equity earnings

-228,592

[2]

-76,181

[2]

-70,254

[2]

-57,249

[2]

-381,902

[3]

-42,984

[3]

-93,871

[3]

-5,434

[3]

-432,276

-524,191

146,910

Income tax benefit (expense)

'

'

'

'

'

'

'

'

70,943

54,075

-28,576

Equity in results of affiliates

'

'

'

'

'

'

'

'

-9,169

-3,490

0

(Loss) income from continuing operations

'

'

'

'

'

'

'

'

-370,502

-473,606

118,334

Loss from discontinued operations, net of tax

'

'

'

'

'

'

'

'

-6,427

-1,737

0

Net (loss) income

-198,288

-69,799

-70,689

-38,153

-389,490

-15,451

-66,924

-3,478

-376,929

-475,343

118,334

Net loss (income) attributable to noncontrolling interests

'

'

'

'

'

'

'

'

2,546

-5,826

-808

Net (loss) income attributable to Molycorp stockholders

-194,308

-69,929

-71,175

-38,971

-391,196

-18,891

-67,604

-3,478

-374,383

-481,169

117,526

Other comprehensive income (loss), net of tax:

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments

'

'

'

'

'

'

'

'

1,623

248

-8,481

Actuarial gain (loss)

'

'

'

'

'

'

'

'

1,359

-1,200

0

Comprehensive (loss) income

'

'

'

'

'

'

'

'

-373,947

-476,295

109,853

Comprehensive (loss) income attributable to:

'

'

'

'

'

'

'

'

'

'

'

Molycorp stockholders

'

'

'

'

'

'

'

'

-376,493

-470,469

109,468

Noncontrolling interests

'

'

'

'

'

'

'

'

2,546

-5,826

385

Parent

'

'

'

'

'

'

'

'

'

'

'

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

0

0

0

Costs of sales:

'

'

'

'

'

'

'

'

'

'

'

Costs excluding depreciation and amortization

'

'

'

'

'

'

'

'

0

0

0

Depreciation and amortization

'

'

'

'

'

'

'

'

0

0

0

Gross (loss) profit

'

'

'

'

'

'

'

'

0

0

0

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Selling, general and administrative

'

'

'

'

'

'

'

'

-190

46

-7

Corporate development

'

'

'

'

'

'

'

'

0

-46

0

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

0

0

0

Research and development

'

'

'

'

'

'

'

'

0

0

0

Impairment of goodwill and other long-lived assets

'

'

'

'

'

'

'

'

0

0

'

Operating (loss) income

'

'

'

'

'

'

'

'

-190

0

-7

Other (expense) income:

'

'

'

'

'

'

'

'

'

'

'

Other income (expense)

'

'

'

'

'

'

'

'

5

-37,589

0

Foreign exchange gain (loss), net

'

'

'

'

'

'

'

'

-9,896

0

0

Interest expense, net of capitalized interest

'

'

'

'

'

'

'

'

-64,392

-18,118

-499

Interest income (expense) from intercompany notes

'

'

'

'

'

'

'

'

36,724

25,157

424

Equity earnings from consolidated subsidiaries

'

'

'

'

'

'

'

'

-330,604

-456,649

117,608

Total other expense

'

'

'

'

'

'

'

'

-368,163

-487,199

117,533

(Loss) income from continuing operations before income taxes and equity earnings

'

'

'

'

'

'

'

'

-368,353

-487,199

117,526

Income tax benefit (expense)

'

'

'

'

'

'

'

'

-6,030

6,030

0

Equity in results of affiliates

'

'

'

'

'

'

'

'

0

0

'

(Loss) income from continuing operations

'

'

'

'

'

'

'

'

-374,383

-481,169

'

Loss from discontinued operations, net of tax

'

'

'

'

'

'

'

'

0

0

'

Net (loss) income

'

'

'

'

'

'

'

'

-374,383

-481,169

117,526

Net loss (income) attributable to noncontrolling interests

'

'

'

'

'

'

'

'

0

0

0

Net (loss) income attributable to Molycorp stockholders

'

'

'

'

'

'

'

'

-374,383

-481,169

117,526

Other comprehensive income (loss), net of tax:

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments

'

'

'

'

'

'

'

'

0

0

0

Actuarial gain (loss)

'

'

'

'

'

'

'

'

0

0

'

Comprehensive (loss) income

'

'

'

'

'

'

'

'

-374,383

-481,169

117,526

Comprehensive (loss) income attributable to:

'

'

'

'

'

'

'

'

'

'

'

Molycorp stockholders

'

'

'

'

'

'

'

'

-374,383

-481,169

117,526

Noncontrolling interests

'

'

'

'

'

'

'

'

0

0

0

Guarantor Subsidiaries

'

'

'

'

'

'

'

'

'

'

'

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

88,266

139,257

365,490

Costs of sales:

'

'

'

'

'

'

'

'

'

'

'

Costs excluding depreciation and amortization

'

'

'

'

'

'

'

'

-200,650

-153,461

-158,951

Depreciation and amortization

'

'

'

'

'

'

'

'

-40,220

-12,094

-9,411

Gross (loss) profit

'

'

'

'

'

'

'

'

-152,604

-26,298

197,128

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Selling, general and administrative

'

'

'

'

'

'

'

'

-66,132

-86,493

-48,296

Corporate development

'

'

'

'

'

'

'

'

-247

-19,750

-5,912

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-6,424

-2,220

-1,378

Research and development

'

'

'

'

'

'

'

'

-5,069

-12,984

-7,718

Impairment of goodwill and other long-lived assets

'

'

'

'

'

'

'

'

-14,250

-5,747

'

Operating (loss) income

'

'

'

'

'

'

'

'

-244,726

-153,492

133,824

Other (expense) income:

'

'

'

'

'

'

'

'

'

'

'

Other income (expense)

'

'

'

'

'

'

'

'

-7,242

-328

-153

Foreign exchange gain (loss), net

'

'

'

'

'

'

'

'

11

0

0

Interest expense, net of capitalized interest

'

'

'

'

'

'

'

'

3,807

-3,496

248

Interest income (expense) from intercompany notes

'

'

'

'

'

'

'

'

-2,493

3,152

-296

Equity earnings from consolidated subsidiaries

'

'

'

'

'

'

'

'

-7,674

-23,205

12,485

Total other expense

'

'

'

'

'

'

'

'

-13,591

-23,877

12,284

(Loss) income from continuing operations before income taxes and equity earnings

'

'

'

'

'

'

'

'

-258,317

-177,369

146,108

Income tax benefit (expense)

'

'

'

'

'

'

'

'

23,130

53,840

-28,500

Equity in results of affiliates

'

'

'

'

'

'

'

'

-6,529

-2,439

'

(Loss) income from continuing operations

'

'

'

'

'

'

'

'

-241,716

-125,968

'

Loss from discontinued operations, net of tax

'

'

'

'

'

'

'

'

0

0

'

Net (loss) income

'

'

'

'

'

'

'

'

-241,716

-125,968

117,608

Net loss (income) attributable to noncontrolling interests

'

'

'

'

'

'

'

'

0

0

0

Net (loss) income attributable to Molycorp stockholders

'

'

'

'

'

'

'

'

-241,716

-125,968

117,608

Other comprehensive income (loss), net of tax:

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments

'

'

'

'

'

'

'

'

0

0

0

Actuarial gain (loss)

'

'

'

'

'

'

'

'

0

0

'

Comprehensive (loss) income

'

'

'

'

'

'

'

'

-241,716

-125,968

117,608

Comprehensive (loss) income attributable to:

'

'

'

'

'

'

'

'

'

'

'

Molycorp stockholders

'

'

'

'

'

'

'

'

-241,716

-125,968

117,608

Noncontrolling interests

'

'

'

'

'

'

'

'

0

0

0

Non-Guarantor Subsidiaries

'

'

'

'

'

'

'

'

'

'

'

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

517,202

413,951

100,398

Costs of sales:

'

'

'

'

'

'

'

'

'

'

'

Costs excluding depreciation and amortization

'

'

'

'

'

'

'

'

-404,259

-350,304

-74,457

Depreciation and amortization

'

'

'

'

'

'

'

'

-27,507

-18,527

-4,128

Gross (loss) profit

'

'

'

'

'

'

'

'

85,436

45,120

21,813

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Selling, general and administrative

'

'

'

'

'

'

'

'

-40,847

-26,990

-2,454

Corporate development

'

'

'

'

'

'

'

'

0

0

0

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

-31,613

-19,967

-310

Research and development

'

'

'

'

'

'

'

'

-18,103

-14,812

0

Impairment of goodwill and other long-lived assets

'

'

'

'

'

'

'

'

-106,648

-296,008

'

Operating (loss) income

'

'

'

'

'

'

'

'

-111,775

-312,657

19,049

Other (expense) income:

'

'

'

'

'

'

'

'

'

'

'

Other income (expense)

'

'

'

'

'

'

'

'

-288

-881

0

Foreign exchange gain (loss), net

'

'

'

'

'

'

'

'

9,509

2,872

-5,415

Interest expense, net of capitalized interest

'

'

'

'

'

'

'

'

-7,099

-502

-137

Interest income (expense) from intercompany notes

'

'

'

'

'

'

'

'

-34,231

-28,309

-128

Equity earnings from consolidated subsidiaries

'

'

'

'

'

'

'

'

0

0

0

Total other expense

'

'

'

'

'

'

'

'

-32,109

-26,820

-5,680

(Loss) income from continuing operations before income taxes and equity earnings

'

'

'

'

'

'

'

'

-143,884

-339,477

13,369

Income tax benefit (expense)

'

'

'

'

'

'

'

'

53,843

-5,795

-76

Equity in results of affiliates

'

'

'

'

'

'

'

'

-2,640

-1,051

'

(Loss) income from continuing operations

'

'

'

'

'

'

'

'

-92,681

-346,323

'

Loss from discontinued operations, net of tax

'

'

'

'

'

'

'

'

-6,427

-1,737

'

Net (loss) income

'

'

'

'

'

'

'

'

-99,108

-348,060

13,293

Net loss (income) attributable to noncontrolling interests

'

'

'

'

'

'

'

'

2,546

-5,826

-808

Net (loss) income attributable to Molycorp stockholders

'

'

'

'

'

'

'

'

-96,562

-353,886

12,485

Other comprehensive income (loss), net of tax:

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments

'

'

'

'

'

'

'

'

1,623

248

-8,481

Actuarial gain (loss)

'

'

'

'

'

'

'

'

1,359

-1,200

'

Comprehensive (loss) income

'

'

'

'

'

'

'

'

-96,126

-349,012

4,812

Comprehensive (loss) income attributable to:

'

'

'

'

'

'

'

'

'

'

'

Molycorp stockholders

'

'

'

'

'

'

'

'

-98,672

-343,186

4,427

Noncontrolling interests

'

'

'

'

'

'

'

'

2,546

-5,826

385

Eliminations

'

'

'

'

'

'

'

'

'

'

'

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

-51,078

-25,512

-69,057

Costs of sales:

'

'

'

'

'

'

'

'

'

'

'

Costs excluding depreciation and amortization

'

'

'

'

'

'

'

'

51,078

25,512

69,057

Depreciation and amortization

'

'

'

'

'

'

'

'

0

0

0

Gross (loss) profit

'

'

'

'

'

'

'

'

0

0

0

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Selling, general and administrative

'

'

'

'

'

'

'

'

0

0

0

Corporate development

'

'

'

'

'

'

'

'

0

0

0

Depreciation, amortization and accretion

'

'

'

'

'

'

'

'

0

0

0

Research and development

'

'

'

'

'

'

'

'

0

0

0

Impairment of goodwill and other long-lived assets

'

'

'

'

'

'

'

'

0

0

'

Operating (loss) income

'

'

'

'

'

'

'

'

0

0

0

Other (expense) income:

'

'

'

'

'

'

'

'

'

'

'

Other income (expense)

'

'

'

'

'

'

'

'

0

0

0

Foreign exchange gain (loss), net

'

'

'

'

'

'

'

'

0

0

0

Interest expense, net of capitalized interest

'

'

'

'

'

'

'

'

0

0

0

Interest income (expense) from intercompany notes

'

'

'

'

'

'

'

'

0

0

0

Equity earnings from consolidated subsidiaries

'

'

'

'

'

'

'

'

338,278

479,854

-130,093

Total other expense

'

'

'

'

'

'

'

'

338,278

479,854

-130,093

(Loss) income from continuing operations before income taxes and equity earnings

'

'

'

'

'

'

'

'

338,278

479,854

-130,093

Income tax benefit (expense)

'

'

'

'

'

'

'

'

0

0

0

Equity in results of affiliates

'

'

'

'

'

'

'

'

0

0

'

(Loss) income from continuing operations

'

'

'

'

'

'

'

'

338,278

479,854

'

Loss from discontinued operations, net of tax

'

'

'

'

'

'

'

'

0

0

'

Net (loss) income

'

'

'

'

'

'

'

'

338,278

479,854

-130,093

Net loss (income) attributable to noncontrolling interests

'

'

'

'

'

'

'

'

0

0

0

Net (loss) income attributable to Molycorp stockholders

'

'

'

'

'

'

'

'

338,278

479,854

-130,093

Other comprehensive income (loss), net of tax:

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments

'

'

'

'

'

'

'

'

0

0

0

Actuarial gain (loss)

'

'

'

'

'

'

'

'

0

0

'

Comprehensive (loss) income

'

'

'

'

'

'

'

'

338,278

479,854

-130,093

Comprehensive (loss) income attributable to:

'

'

'

'

'

'

'

'

'

'

'

Molycorp stockholders

'

'

'

'

'

'

'

'

338,278

479,854

-130,093

Noncontrolling interests

'

'

'

'

'

'

'

'

$0

$0

$0

[1]

Includes impairment of goodwill and other long-lived assets in some segments. See notes 7 and 9 below for details.

[2]

Includes the following impairment charges in the fourth quarter: goodwill, $11.0 million; rare earths quotas, $67.2 million; patents, $10.2 million; exploration rights, $16.2 million; cost-method investments $9.4 million and long-lived tangible assets, $16.3 million.

[3]

The sum of the quarterly income (loss) per share may be different than the per share amount for the year as the calculation for each quarter is based on the weighted average shares outstanding for that period.

Condensed_Consolidating_Statem1

Condensed Consolidating Statements of Cash Flows (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'	'
Net cash (used in) provided by operating activities	($154,351,000)	($89,635,000)	$42,965,000
Cash flows from investing activities:	'	'	'
Cash paid in connection with acquisitions, net of cash acquired	0	-591,011,000	-30,023,000
Cash paid to acquire non-marketable securities	0	0	-20,000,000
Loans to guarantor	0	'	'
Loans to subsidiaries	'	0	0
Loans to Parent	0	0	'
Intercompany advances made	0	0	0
Loans to non-guarantor	0	0	'
Repayments from subsidiaries	'	0	'
Investment in subsidiaries	'	0	'
Notes receivable to non-guarantor	0	0	'
Repayments of notes receivable from non-guarantor	0	0	'
Investment in joint ventures	-3,423,000	-33,044,000	0
Deposits	0	-3,999,000	2,897,000
Capital expenditures	-379,312,000	-791,469,000	-302,180,000
Acquisition of exploration rights	0	-8,167,000	0
Other investing activities	5,477,000	4,761,000	-84,000
Net cash used in investing activities	-377,258,000	-1,422,929,000	-349,390,000
Cash flows from financing activities:	'	'	'
Issuance of shares to Molymet	0	390,093,000	0
Capital contributions from parent company	'	0	'
Repayments of short-term borrowings—related party	0	0	-3,150,000
Repayments of debt	-26,823,000	-228,708,000	-4,428,000
Net proceeds from sale of preferred stock	0	0	199,642,000
Net proceeds from sale of common stock	495,717,000	132,130,000	0
Issuance of 10% Senior Secured Notes	'	635,373,000	'
Issuance of 5.50% Convertible Notes	165,600,000	395,712,000	223,100,000
Payments of preferred dividends	-11,385,000	-11,385,000	-9,015,000
Distribution paid to noncontrolling interests	-4,546,000	-5,977,000	0
Borrowing from non-guarantor	0	'	'
Proceeds from debt	0	14,699,000	5,131,000
Borrowings from parent	0	0	0
Repayments of borrowings to parent	0	0	'
Borrowing from guarantor	0	0	'
Repayments of borrowings to guarantor	0	0	'
Intercompany advances owed	0	0	0
Other financing activities	-1,297,000	-1,554,000	0
Net cash provided by financing activities	617,266,000	1,320,383,000	411,280,000
Effect of exchange rate changes on cash	870,000	1,116,000	-2,430,000
Net change in cash and cash equivalents	86,527,000	-191,065,000	102,425,000
Cash and cash equivalents at beginning of the period	227,790,000	418,855,000	316,430,000
Cash and cash equivalents at end of period	314,317,000	227,790,000	418,855,000
Parent	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'
Net cash (used in) provided by operating activities	-39,075,000	-13,207,000	903,000
Cash flows from investing activities:	'	'	'
Cash paid in connection with acquisitions, net of cash acquired	'	0	0
Cash paid to acquire non-marketable securities	'	'	0
Loans to guarantor	0	'	'
Loans to subsidiaries	'	-683,063,000	-49,430,000
Loans to Parent	0	0	'
Intercompany advances made	-391,560,000	-1,009,014,000	-290,633,000
Loans to non-guarantor	-117,512,000	0	'
Repayments from subsidiaries	'	87,824,000	'
Investment in subsidiaries	'	-350,000,000	'
Notes receivable to non-guarantor	-117,512,000	0	'
Repayments of notes receivable from non-guarantor	38,000,000	0	'
Investment in joint ventures	0	0	'
Deposits	'	0	16,449,000
Capital expenditures	0	0	0
Acquisition of exploration rights	'	0	'
Other investing activities	0	0	0
Net cash used in investing activities	-471,072,000	-1,954,253,000	-323,614,000
Cash flows from financing activities:	'	'	'
Issuance of shares to Molymet	'	390,093,000	'
Capital contributions from parent company	'	0	'
Repayments of short-term borrowings—related party	'	'	0
Repayments of debt	0	0	0
Net proceeds from sale of preferred stock	'	'	199,642,000
Net proceeds from sale of common stock	495,717,000	132,130,000	'
Issuance of 10% Senior Secured Notes	'	635,373,000	'
Issuance of 5.50% Convertible Notes	165,600,000	395,712,000	223,100,000
Payments of preferred dividends	-11,385,000	-11,385,000	-9,015,000
Distribution paid to noncontrolling interests	0	0	'
Borrowing from non-guarantor	12,800,000	'	'
Proceeds from debt	'	0	0
Borrowings from parent	0	0	0
Repayments of borrowings to parent	0	0	'
Borrowing from guarantor	0	37,589,000	'
Repayments of borrowings to guarantor	0	0	'
Intercompany advances owed	0	0	0
Other financing activities	0	-2,938,000	'
Net cash provided by financing activities	662,732,000	1,576,574,000	413,727,000
Effect of exchange rate changes on cash	0	0	0
Net change in cash and cash equivalents	152,585,000	-390,886,000	91,016,000
Cash and cash equivalents at beginning of the period	16,560,000	407,446,000	316,430,000
Cash and cash equivalents at end of period	169,145,000	16,560,000	407,446,000
Guarantor Subsidiaries	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'
Net cash (used in) provided by operating activities	-133,612,000	-112,386,000	44,211,000
Cash flows from investing activities:	'	'	'
Cash paid in connection with acquisitions, net of cash acquired	'	0	-30,128,000
Cash paid to acquire non-marketable securities	'	'	-20,000,000
Loans to guarantor	0	'	'
Loans to subsidiaries	'	0	0
Loans to Parent	0	-37,589,000	'
Intercompany advances made	0	0	0
Loans to non-guarantor	-1,300,000	-227,512,000	'
Repayments from subsidiaries	'	0	'
Investment in subsidiaries	'	0	'
Notes receivable to non-guarantor	-1,300,000	-227,512,000	'
Repayments of notes receivable from non-guarantor	117,776,000	110,000,000	'
Investment in joint ventures	-3,423,000	-27,680,000	'
Deposits	'	-3,999,000	-13,552,000
Capital expenditures	-361,782,000	-766,951,000	-294,010,000
Acquisition of exploration rights	'	0	'
Other investing activities	4,902,000	0	16,000
Net cash used in investing activities	-243,827,000	-953,731,000	-357,674,000
Cash flows from financing activities:	'	'	'
Issuance of shares to Molymet	'	0	'
Capital contributions from parent company	'	0	'
Repayments of short-term borrowings—related party	'	'	-3,150,000
Repayments of debt	0	-870,000	0
Net proceeds from sale of preferred stock	'	'	0
Net proceeds from sale of common stock	0	0	'
Issuance of 10% Senior Secured Notes	'	0	'
Issuance of 5.50% Convertible Notes	0	0	0
Payments of preferred dividends	0	0	0
Distribution paid to noncontrolling interests	0	0	'
Borrowing from non-guarantor	40,000,000	'	'
Proceeds from debt	'	0	0
Borrowings from parent	0	227,512,000	37,370,000
Repayments of borrowings to parent	0	-34,327,000	'
Borrowing from guarantor	0	0	'
Repayments of borrowings to guarantor	0	0	'
Intercompany advances owed	327,183,000	881,179,000	290,001,000
Other financing activities	-1,297,000	-115,000	'
Net cash provided by financing activities	365,886,000	1,073,379,000	324,221,000
Effect of exchange rate changes on cash	0	0	0
Net change in cash and cash equivalents	-11,553,000	7,262,000	10,758,000
Cash and cash equivalents at beginning of the period	18,020,000	10,758,000	0
Cash and cash equivalents at end of period	6,467,000	18,020,000	10,758,000
Non-Guarantor Subsidiaries	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'
Net cash (used in) provided by operating activities	18,336,000	35,958,000	-2,149,000
Cash flows from investing activities:	'	'	'
Cash paid in connection with acquisitions, net of cash acquired	'	-591,011,000	105,000
Cash paid to acquire non-marketable securities	'	'	0
Loans to guarantor	-40,000,000	'	'
Loans to subsidiaries	'	0	0
Loans to Parent	-12,800,000	0	'
Intercompany advances made	0	0	0
Loans to non-guarantor	0	0	'
Repayments from subsidiaries	'	0	'
Investment in subsidiaries	'	0	'
Notes receivable to non-guarantor	0	0	'
Repayments of notes receivable from non-guarantor	0	0	'
Investment in joint ventures	0	-5,364,000	'
Deposits	'	0	0
Capital expenditures	-17,530,000	-24,518,000	-8,170,000
Acquisition of exploration rights	'	-8,167,000	'
Other investing activities	575,000	4,761,000	-100,000
Net cash used in investing activities	-69,755,000	-624,299,000	-8,165,000
Cash flows from financing activities:	'	'	'
Issuance of shares to Molymet	'	0	'
Capital contributions from parent company	'	350,000,000	'
Repayments of short-term borrowings—related party	'	'	0
Repayments of debt	-26,823,000	-227,838,000	-4,428,000
Net proceeds from sale of preferred stock	'	'	0
Net proceeds from sale of common stock	0	0	'
Issuance of 10% Senior Secured Notes	'	0	'
Issuance of 5.50% Convertible Notes	0	0	0
Payments of preferred dividends	0	0	0
Distribution paid to noncontrolling interests	-4,546,000	-5,977,000	'
Borrowing from non-guarantor	0	'	'
Proceeds from debt	'	14,699,000	5,131,000
Borrowings from parent	117,512,000	455,551,000	12,060,000
Repayments of borrowings to parent	-38,000,000	-53,497,000	'
Borrowing from guarantor	1,300,000	227,512,000	'
Repayments of borrowings to guarantor	-117,776,000	-110,000,000	'
Intercompany advances owed	64,377,000	127,835,000	632,000
Other financing activities	0	1,499,000	'
Net cash provided by financing activities	-3,956,000	779,784,000	13,395,000
Effect of exchange rate changes on cash	870,000	1,116,000	-2,430,000
Net change in cash and cash equivalents	-54,505,000	192,559,000	651,000
Cash and cash equivalents at beginning of the period	193,210,000	651,000	0
Cash and cash equivalents at end of period	138,705,000	193,210,000	651,000
Eliminations	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'
Net cash (used in) provided by operating activities	0	0	0
Cash flows from investing activities:	'	'	'
Cash paid in connection with acquisitions, net of cash acquired	'	0	0
Cash paid to acquire non-marketable securities	'	'	0
Loans to guarantor	40,000,000	'	'
Loans to subsidiaries	'	683,063,000	49,430,000
Loans to Parent	12,800,000	37,589,000	'
Intercompany advances made	391,560,000	1,009,014,000	290,633,000
Loans to non-guarantor	118,812,000	227,512,000	'
Repayments from subsidiaries	'	-87,824,000	'
Investment in subsidiaries	'	350,000,000	'
Notes receivable to non-guarantor	118,812,000	227,512,000	'
Repayments of notes receivable from non-guarantor	-155,776,000	-110,000,000	'
Investment in joint ventures	0	0	'
Deposits	'	0	0
Capital expenditures	0	0	0
Acquisition of exploration rights	'	0	'
Other investing activities	0	0	0
Net cash used in investing activities	407,396,000	2,109,354,000	340,063,000
Cash flows from financing activities:	'	'	'
Issuance of shares to Molymet	'	0	'
Capital contributions from parent company	'	-350,000,000	'
Repayments of short-term borrowings—related party	'	'	0
Repayments of debt	0	0	0
Net proceeds from sale of preferred stock	'	'	0
Net proceeds from sale of common stock	0	0	'
Issuance of 10% Senior Secured Notes	'	0	'
Issuance of 5.50% Convertible Notes	0	0	0
Payments of preferred dividends	0	0	0
Distribution paid to noncontrolling interests	0	0	'
Borrowing from non-guarantor	-52,800,000	'	'
Proceeds from debt	'	0	0
Borrowings from parent	-117,512,000	-683,063,000	-49,430,000
Repayments of borrowings to parent	38,000,000	87,824,000	'
Borrowing from guarantor	-1,300,000	-265,101,000	'
Repayments of borrowings to guarantor	117,776,000	110,000,000	'
Intercompany advances owed	-391,560,000	-1,009,014,000	-290,633,000
Other financing activities	0	0	'
Net cash provided by financing activities	-407,396,000	-2,109,354,000	-340,063,000
Effect of exchange rate changes on cash	0	0	0
Net change in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of the period	0	0	0
Cash and cash equivalents at end of period	$0	$0	$0

Discontinued_Operations_Detail

Discontinued Operations (Details) (USD $)	12 Months Ended				7 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
				Prepaid Expenses and Other Current Assets	Napanee Facility	Napanee Facility
						acre
						building
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'	'	'
Number of buildings	'	'	'	'	'	2
Number of acres	'	'	'	'	'	2
Assets of Disposal Group, Including Discontinued Operation [Abstract]	'	'	'	'	'	'
Land	'	'	'	$25	'	'
Buildings	'	'	'	250	'	'
Equipment	'	'	'	250	'	'
Inventory	'	'	'	475	'	'
Carrying value of disposal group	'	'	'	1,000	'	'
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]	'	'	'	'	'	'
Revenues	'	'	'	'	1,214	2,091
Costs of sales	'	'	'	'	-2,691	-3,834
Selling, general and administrative expenses	'	'	'	'	-232	-351
Depreciation	'	'	'	'	-28	-28
Operating loss	'	'	'	'	-1,737	-2,122
Loss on assets impairment	'	'	'	'	0	-4,305
Income tax	'	'	'	'	0	0
Net loss	($6,427)	($1,737)	$0	'	($1,737)	($6,427)

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Details) (Fair Value, Measurements, Recurring, USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets:	'	'
Cash equivalents	$179,052	$58,253
Liabilities:	'	'
Derivative liability	6,089	7,816
Level 1	'	'
Assets:	'	'
Cash equivalents	179,052	58,253
Liabilities:	'	'
Derivative liability	0	0
Level 2	'	'
Assets:	'	'
Cash equivalents	0	0
Liabilities:	'	'
Derivative liability	0	0
Level 3	'	'
Assets:	'	'
Cash equivalents	0	0
Liabilities:	'	'
Derivative liability	$6,089	$7,816

Liability_Carrying_and_Fair_Va

Liability Carrying and Fair Value (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Carrying Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	$1,339,369	$1,166,777
Carrying Value | 3.25% Convertible Notes | Convertible Debt | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	207,028	198,689
Carrying Value | 6.00% Convertible Notes | Convertible Debt | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	346,708	331,977
Carrying Value | 5.50% Convertible Senior Notes due 2018 | Convertible Debt | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	148,198	'
Carrying Value | 10% Senior Securied Notes, net of discount, due June 2020 | Senior Notes | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	637,435	636,111
Fair Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	1,285,106	572,507
Fair Value | 3.25% Convertible Notes | Convertible Debt | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	161,771	159,542
Fair Value | 6.00% Convertible Notes | Convertible Debt | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	312,570	412,965
Fair Value | 5.50% Convertible Senior Notes due 2018 | Convertible Debt | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	164,015	'
Fair Value | 10% Senior Securied Notes, net of discount, due June 2020 | Senior Notes | Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	$646,750	'

Unaudited_Supplementary_Data_D

Unaudited Supplementary Data (Details) (USD $)

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Magnetic Materials and Alloys

Magnetic Materials and Alloys

Molycorp Canada

Exploration rights

Exploration rights

Rare earths quotas

Patents

Total Molycorp Stockholders' Equity

Molycorp Canada

Magnetic Materials and Alloys

Quarterly Financial Information Disclosure [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

$123,814,000

$149,066,000

$136,112,000

$145,398,000

$133,611,000

$205,205,000

$104,410,000

$84,470,000

$554,390,000

$527,696,000

$396,831,000

$252,713,000

'

'

'

'

'

'

'

Gross profit

-27,049,000

-17,778,000

-18,036,000

-4,305,000

-19,703,000

11,494,000

-3,996,000

31,027,000

-67,168,000

18,822,000

218,941,000

'

'

'

'

'

'

'

'

Loss before income taxes and equity earnings

-228,592,000

[1]

-76,181,000

[1]

-70,254,000

[1]

-57,249,000

[1]

-381,902,000

[2]

-42,984,000

[2]

-93,871,000

[2]

-5,434,000

[2]

-432,276,000

-524,191,000

146,910,000

62,107,000

'

'

'

'

'

'

'

Net (loss) income

-198,288,000

-69,799,000

-70,689,000

-38,153,000

-389,490,000

-15,451,000

-66,924,000

-3,478,000

-376,929,000

-475,343,000

118,334,000

'

'

'

'

'

'

'

'

Net (loss) income attributable to Molycorp stockholders

-194,308,000

-69,929,000

-71,175,000

-38,971,000

-391,196,000

-18,891,000

-67,604,000

-3,478,000

-374,383,000

-481,169,000

117,526,000

'

'

'

'

'

'

'

'

(Loss) income per share of common stock:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Basic (in dollars per share)

($0.95)

($0.43)

($0.44)

($0.27)

($3.16)

($0.19)

($0.71)

($0.07)

($2.21)

($4.60)

$1.29

'

'

'

'

'

'

'

'

Diluted (in dollars per share)

($0.95)

($0.43)

($0.44)

($0.27)

($3.16)

($0.19)

($0.71)

($0.07)

($2.21)

($4.60)

$1.27

'

'

'

'

'

'

'

'

Quarterly Financial Data [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of goodwill and other intangible assets

11,000,000

'

'

'

'

'

'

'

10,992,000

289,894,000

'

0

112,694,000

287,900,000

'

'

'

'

'

Impairment of goodwill and other long-lived assets

'

'

'

'

'

'

'

'

120,898,000

301,755,000

0

'

'

'

'

'

67,200,000

10,200,000

6,000,000

Tangible Asset Impairment Charges

'

'

'

'

'

'

'

'

16,300,000

5,900,000

'

'

'

'

16,200,000

16,200,000

'

'

'

Impairment of cost-method investment

$9,400,000

'

'

'

'

'

'

'

$9,411,000

$0

$0

'

'

'

'

'

'

'

'

[1]

Includes the following impairment charges in the fourth quarter: goodwill, $11.0 million; rare earths quotas, $67.2 million; patents, $10.2 million; exploration rights, $16.2 million; cost-method investments $9.4 million and long-lived tangible assets, $16.3 million.

[2]

The sum of the quarterly income (loss) per share may be different than the per share amount for the year as the calculation for each quarter is based on the weighted average shares outstanding for that period.

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent Event, USD $)	0 Months Ended
	Feb. 05, 2014	Mar. 01, 2014
Subsequent Event	'	'
Subsequent Events	'	'
Cash dividend declared (in dollars per share)	$1.38	'
Preferred shares issued upon conversion	'	4,140,000