Stillwater Mining (SWC) 10-K 3 Mar 14 2013 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 25, 2014	Jun. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Entity Registrant Name	'STILLWATER MINING CO /DE/	'	'
Entity Central Index Key	'0000931948	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	119,629,040	'
Entity Public Float	'	'	$1.30
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive (Loss) Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
REVENUES	'	'	'
Mine Production	$478,918	$455,426	$528,007
PGM Recycling	560,588	344,818	376,820
Other	0	0	1,142
Total revenues	1,039,506	800,244	905,969
Costs of metals sold	'	'	'
Mine Production	313,963	288,922	269,573
PGM Recycling	527,384	334,949	358,566
Other	0	0	1,141
Total costs of metals sold (excludes depletion, depreciation and amortization)	841,347	623,871	629,280
Depletion, depreciation and amortization	'	'	'
Mine Production	58,201	56,960	61,312
PGM Recycling	1,116	1,055	1,066
Total depletion, depreciation and amortization	59,317	58,015	62,378
Total costs of revenues	900,664	681,886	691,658
Loss on inventory purchases	0	590	600
Loss on trade receivables	632	0	0
Loss/(Gain) on disposal of property, plant and equipment	68	448	-128
Research and development	237	1,159	2,238
Loss on long-term investments	1,894	2,562	0
Impairment of non-producing mineral properties and property, plant and equipment	461,755	0	0
Abandonment of non-producing property	0	2,835	0
Marketing	4,355	11,170	11,810
Exploration	11,169	15,010	2,513
Proxy contest expense	4,307	0	0
Accelerated equity based compensation expense	9,063	0	0
General and administrative	41,985	40,948	42,072
Total costs and expenses	1,436,129	756,608	750,763
OPERATING (LOSS) INCOME	-396,623	43,636	155,206
OTHER INCOME (EXPENSE)	'	'	'
Other	1,173	181	68
Interest income	4,481	2,325	3,574
Interest expense	-22,957	-10,920	-6,548
Foreign currency transaction gain, net	18,200	15,155	3,230
(LOSS) INCOME BEFORE INCOME TAX BENEFIT (PROVISION)	-395,726	50,377	155,530
Income tax benefit (provision)	93,653	4,039	-11,235
NET (LOSS) INCOME	-302,073	54,416	144,295
Net (loss) income attributable to noncontrolling interest	-31,867	-629	0
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS	-270,206	55,045	144,295
Other comprehensive (loss) income, net of tax	'	'	'
Net unrealized gains/(losses) on investments available-for-sale	105	862	-109
COMPREHENSIVE (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS	-270,101	55,907	144,186
Comprehensive (loss) income attributable to noncontrolling interest	-31,867	-629	0
TOTAL COMPREHENSIVE (LOSS) INCOME	($301,968)	$55,278	$144,186
Weighted average common shares outstanding	'	'	'
Basic (in shares)	118,607	116,162	105,846
Diluted (in shares)	118,607	131,441	113,946
Basic (loss) earnings per share attributable to common stockholders	($2.28)	$0.47	$1.36
Diluted (loss) earnings per share attributable to common stockholders	($2.28)	$0.46	$1.30

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$286,687	$379,680
Investments, at fair market value	209,338	261,983
Inventories	158,650	153,208
Trade receivables	8,988	9,953
Deferred income taxes	21,547	21,304
Prepaids	3,912	5,020
Other current assets	14,757	21,714
Total current assets	703,879	852,862
Mineral properties	159,252	576,359
Mine development, net	346,346	322,866
Property, plant and equipment, net	124,731	122,677
Deferred debt issuance costs	7,945	9,609
Other noncurrent assets	4,527	6,390
Total assets	1,346,680	1,890,763
Current liabilities	'	'
Accounts payable	32,088	28,623
Accrued compensation and benefits	30,646	31,369
Property, production and franchise taxes payable	14,495	13,722
Current portion of long-term debt and capital lease obligations	2,035	168,432
Income taxes payable	4,416	0
Other current liabilities	5,368	4,702
Total current liabilities	89,048	246,848
Long-term debt and capital lease obligations	308,667	292,685
Deferred income taxes	79,159	199,802
Accrued workers compensation	6,031	5,815
Asset retirement obligation	8,654	7,965
Other noncurrent liabilities	7,262	5,068
Total liabilities	498,821	758,183
Stockholders’ equity	'	'
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued	0	0
Common stock, $0.01 par value, 200,000,000 shares authorized; 119,466,449 and 116,951,081 shares issued and outstanding	1,195	1,170
Paid-in capital	1,076,200	1,058,978
Accumulated (deficit) earnings	-249,436	20,770
Accumulated other comprehensive income (loss)	6	-99
Total stockholders’ equity	827,965	1,080,819
Noncontrolling interest	19,894	51,761
Total equity	847,859	1,132,580
Total liabilities and equity	$1,346,680	$1,890,763

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Preferred stock	'	'
Preferred stock, par value (in usd per share)	$0.01	$0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock	'	'
Common stock, par value (in usd per share)	$0.01	$0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	119,466,449	116,951,081
Common stock, shares outstanding	119,466,449	116,951,081

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES	'	'	'
Net (loss) income	($302,073)	$54,416	$144,295
Adjustments to reconcile net (loss) income to net cash provided by operating activities:	'	'	'
Depletion, depreciation and amortization	59,317	58,015	62,378
Loss on inventory purchases	0	590	600
Loss on trade receivables	632	0	0
Loss on disposal of property, plant and equipment	68	448	-128
Impairment of non-producing mineral properties and property, plant and equipment	461,755	0	0
Loss on long-term investments	1,894	2,562	0
Amortization/accretion on investment premium/discount	3,079	900	359
Deferred taxes	-108,543	-3,937	0
Foreign currency transaction gain, net	-18,200	-15,155	-3,230
Abandonment of non-producing property	0	2,835	0
Accretion of asset retirement obligation	689	634	584
Amortization of debt issuance costs	1,664	1,495	988
Accretion of convertible debenture debt discount	15,783	3,097	0
Accelerated equity based compensation expense	9,063	0	0
Share based compensation and other benefits	15,242	16,369	12,358
Non-cash capitalized interest	-2,878	0	0
Changes in operating assets and liabilities:	'	'	'
Inventories	-4,252	-19,958	-34,143
Trade receivables	333	-3,765	1,192
Prepaids	1,108	39	-2,312
Accrued compensation and benefits	-723	3,575	2,822
Accounts payable	3,187	-1,772	4,012
Property, production and franchise taxes payable	2,006	-970	4,338
Income taxes payable	4,416	-1,235	1,235
Workers compensation	216	-241	-1,099
Restricted cash	0	25,035	13,000
Excess tax benefit from share-based compensation	-2,756	-7,737	0
Other operating assets	6,790	-2,250	10,704
Other operating liabilities	1,616	-9,096	1,730
NET CASH PROVIDED BY OPERATING ACTIVITIES	149,433	103,894	219,683
CASH FLOWS FROM INVESTING ACTIVITIES	'	'	'
Capital expenditures	-129,029	-112,071	-101,940
Purchase of Peregrine Metals Ltd. assets	0	0	-166,361
Purchase of long-term investment	0	0	-616
Proceeds from disposal of property, plant and equipment	218	222	277
Purchases of investments	-151,567	-280,273	-106,417
Proceeds from maturities of investments	201,255	67,314	245,464
NET CASH USED IN INVESTING ACTIVITIES	-79,123	-324,808	-129,593
CASH FLOWS FROM FINANCING ACTIVITIES	'	'	'
Proceeds from sale of noncontrolling interest, net of transaction costs	0	93,821	0
Excess tax benefit from stock-based compensation	2,756	7,737	0
Issuance of long-term debt	0	403,926	0
Payments on debt and capital lease obligations	-166,187	-1,394	0
Payments for debt issuance costs	0	-12,637	-1,143
Issuance of common stock	128	44	787
NET CASH (USED IN) PROVIDED BY FINANCING ACTIVITIES	-163,303	491,497	-356
CASH AND CASH EQUIVALENTS	'	'	'
Net (decrease) increase	-92,993	270,583	89,734
Balance at beginning of period	379,680	109,097	19,363
BALANCE AT END OF PERIOD	$286,687	$379,680	$109,097

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Equity (USD $)

Total

Benton Resources Corp. [Member]

Peregrine Metals Ltd. [Member]

Non Employee Directors Deferral Plan [Member]

Common Stock [Member]

Common Stock [Member]

Common Stock [Member]

Common Stock [Member]

Paid-in Capital [Member]

Paid-in Capital [Member]

Paid-in Capital [Member]

Paid-in Capital [Member]

Accumulated Earnings (Deficit) [Member]

Accumulated Other Comprehensive Loss [Member]

Noncontrolling Interest [Member]

In Thousands, except Share data, unless otherwise specified

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Benton Resources Corp. [Member]

Peregrine Metals Ltd. [Member]

Non Employee Directors Deferral Plan [Member]

USD ($)

Benton Resources Corp. [Member]

Peregrine Metals Ltd. [Member]

Non Employee Directors Deferral Plan [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

BALANCE, beginning of year at Dec. 31, 2010

$583,072

'

'

'

$1,019

'

'

'

$761,475

'

'

'

($178,570)

($852)

$0

BALANCE, beginning of year (in shares) at Dec. 31, 2010

'

'

'

'

101,882,000

'

'

'

'

'

'

'

'

'

'

Increase (Decrease) in Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net (loss) income

144,295

'

'

'

'

'

'

'

'

'

'

'

144,295

'

0

Change in fair market value of investments

-109

'

'

'

'

'

'

'

'

'

'

'

'

-109

'

Common stock issued under employee benefit plans (in shares)

'

'

'

'

371,000

'

'

'

'

'

'

'

'

'

'

Common stock issued under employee benefit plans

5,622

'

'

'

4

'

'

'

5,618

'

'

'

'

'

'

Stock option expense

231

'

'

'

'

'

'

'

231

'

'

'

'

'

'

Common stock issued under stock plans (in shares)

52,131

'

'

'

52,000

'

'

'

'

'

'

'

'

'

'

Common stock issued under stock plans

787

'

'

'

0

'

'

'

787

'

'

'

'

'

'

Common stock issued under Directors' deferral plan (in shares)

'

'

'

'

'

'

'

7,000

'

'

'

'

'

'

'

Common stock issued under Directors’ deferral plan

'

'

'

81

'

'

'

'

'

'

'

81

'

'

'

Nonvested shares of common stock granted to officers and employees (in shares)

'

'

'

'

686,000

'

'

'

'

'

'

'

'

'

'

Nonvested shares of common stock granted to officers and employees

7

'

'

'

7

'

'

'

'

'

'

'

'

'

'

Common stock issued for acquisition (in shares)

'

'

'

'

'

348,000

12,030,000

'

'

'

'

'

'

'

'

Common stock issued for acquisition

'

6,919

96,652

'

'

4

120

'

'

6,915

96,532

'

'

'

'

Amortization of unearned nonvested stock

6,453

'

'

'

'

'

'

'

6,453

'

'

'

'

'

'

Forfeiture of nonvested stock

-42

'

'

'

'

'

'

'

-42

'

'

'

'

'

'

BALANCE, end of year at Dec. 31, 2011

843,968

'

'

'

1,154

'

'

'

878,050

'

'

'

-34,275

-961

0

BALANCE, end of year (in shares) at Dec. 31, 2011

'

'

'

'

115,376,000

'

'

'

'

'

'

'

'

'

'

Increase (Decrease) in Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net (loss) income

54,416

'

'

'

'

'

'

'

'

'

'

'

55,045

'

-629

Change in fair market value of investments

862

'

'

'

'

'

'

'

'

'

'

'

'

862

'

Common stock issued under employee benefit plans (in shares)

'

'

'

'

749,000

'

'

'

'

'

'

'

'

'

'

Common stock issued under employee benefit plans

7,898

'

'

'

8

'

'

'

7,890

'

'

'

'

'

'

Income tax benefit on share-based compensation

7,737

'

'

'

'

'

'

'

7,737

'

'

'

'

'

'

Stock option expense

97

'

'

'

'

'

'

'

97

'

'

'

'

'

'

Common stock issued under stock plans (in shares)

16,552

'

'

'

74,000

'

'

'

'

'

'

'

'

'

'

Common stock issued under stock plans

44

'

'

'

1

'

'

'

43

'

'

'

'

'

'

Common stock issued under Directors' deferral plan (in shares)

'

'

'

'

'

'

'

12,000

'

'

'

'

'

'

'

Common stock issued under Directors’ deferral plan

'

'

'

76

'

'

'

'

'

'

'

76

'

'

'

Nonvested shares of common stock granted to officers and employees (in shares)

'

'

'

'

740,000

'

'

'

'

'

'

'

'

'

'

Nonvested shares of common stock granted to officers and employees

54

'

'

'

7

'

'

'

47

'

'

'

'

'

'

Equity component of 1.75% Convertible debenture

137,173

'

'

'

'

'

'

'

137,173

'

'

'

'

'

'

Noncontrolling interest

93,821

'

'

'

'

'

'

'

41,431

'

'

'

'

'

52,390

Valuation allowance

35,799

'

'

'

'

'

'

'

35,799

'

'

'

'

'

'

Deferred taxes on 1.75% Convertible debentures

-57,526

'

'

'

'

'

'

'

-57,526

'

'

'

'

'

'

Amortization of unearned nonvested stock

8,341

'

'

'

'

'

'

'

8,341

'

'

'

'

'

'

Forfeiture of nonvested stock

-180

'

'

'

'

'

'

'

-180

'

'

'

'

'

'

BALANCE, end of year at Dec. 31, 2012

1,132,580

'

'

'

1,170

'

'

'

1,058,978

'

'

'

20,770

-99

51,761

BALANCE, end of year (in shares) at Dec. 31, 2012

116,951,081

'

'

'

116,951,000

'

'

'

'

'

'

'

'

'

'

Increase (Decrease) in Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net (loss) income

-302,073

'

'

'

'

'

'

'

'

'

'

'

-270,206

'

-31,867

Change in fair market value of investments

105

'

'

'

'

'

'

'

'

'

'

'

'

105

'

Common stock issued under employee benefit plans (in shares)

'

'

'

'

873,000

'

'

'

'

'

'

'

'

'

'

Common stock issued under employee benefit plans

10,264

'

'

'

8

'

'

'

10,256

'

'

'

'

'

'

Income tax benefit on share-based compensation

2,756

'

'

'

'

'

'

'

2,756

'

'

'

'

'

'

Stock option expense

41

'

'

'

'

'

'

'

41

'

'

'

'

'

'

Common stock issued under stock plans (in shares)

25,471

'

'

'

25,000

'

'

'

'

'

'

'

'

'

'

Common stock issued under stock plans

128

'

'

'

0

'

'

'

128

'

'

'

'

'

'

Common stock issued under Directors' deferral plan (in shares)

'

'

'

'

'

'

'

53,000

'

'

'

'

'

'

'

Common stock issued under Directors’ deferral plan

'

'

'

315

'

'

'

'

'

'

'

315

'

'

'

Nonvested shares of common stock granted to officers and employees (in shares)

'

'

'

'

1,751,000

'

'

'

'

'

'

'

'

'

'

Nonvested shares of common stock granted to officers and employees

0

'

'

'

18

'

'

'

-18

'

'

'

'

'

'

Canceled shares in excess of plan limit (in shares)

'

'

'

'

-187,000

'

'

'

'

'

'

'

'

'

'

Canceled shares in excess of plan limit

0

'

'

'

-1

'

'

'

1

'

'

'

'

'

'

Valuation allowance

-9,942

'

'

'

'

'

'

'

-9,942

'

'

'

'

'

'

Amortization of unearned nonvested stock

13,687

'

'

'

'

'

'

'

13,687

'

'

'

'

'

'

Forfeiture of nonvested stock

-2

'

'

'

'

'

'

'

-2

'

'

'

'

'

'

BALANCE, end of year at Dec. 31, 2013

$847,859

'

'

'

$1,195

'

'

'

$1,076,200

'

'

'

($249,436)

$6

$19,894

BALANCE, end of year (in shares) at Dec. 31, 2013

119,466,449

'

'

'

119,466,000

'

'

'

'

'

'

'

'

'

'

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Equity (Parenthetical) (1.75% convertible debentures [Member])	Dec. 31, 2013	Dec. 31, 2012	Oct. 31, 2012
1.75% convertible debentures [Member]	'	'	'
Debt instrument, stated rate	1.75%	1.75%	1.75%

Nature_of_Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Nature of Operations	'
	NATURE OF OPERATIONS
	Stillwater Mining Company (the Company) is engaged in the development, extraction, processing, smelting, and refining of palladium, platinum and associated metals (platinum group metals or PGMs) from a geological formation in south-central Montana known as the J-M Reef and from the recycling of spent catalytic converters. The Company is also engaged in expanding its mining operations on the J-M Reef, and holds the Marathon PGM-copper property adjacent to Lake Superior in northern Ontario, Canada and the Altar copper-gold property in the province of San Juan, Argentina.
	The Company conducts mining operations at the Stillwater Mine near Nye, Montana and at the East Boulder Mine south of Big Timber, Montana. Ore extraction at both mines takes place within the J-M Reef. The Company operates concentrating plants at each mining operation to upgrade the mined production into a concentrated form. The Company operates a smelter and base metal refinery at Columbus, Montana which further upgrades the mined concentrates into a PGM-rich filter cake. The filter cake is shipped to third-party refiners for final refining before the contained PGMs are sold to third-parties.
	The Company has three expansion developments along the J-M Reef. The first of these, known as Blitz, will develop underground drifts on two levels from the current Stillwater Mine toward the eastern extremity of the reef. The second development, known as Graham Creek, is now well advanced, expanding to the west in areas adjacent to the existing operations at the East Boulder Mine. The third internal expansion effort, the Lower Far West development, is located within the Stillwater Mine and is utilizing available manpower and resources to accelerate development of an underground mining area located about three miles west of the mineshaft and below the existing Upper West operations.
	Besides processing mine concentrates, the Company also recycles spent catalyst material acquired from third-parties at the smelter and base metal refinery to recover the contained PGMs – palladium, platinum and rhodium. The Company currently has catalyst sourcing arrangements with various suppliers who ship spent catalysts to the Company for processing to recover the PGMs. The Company smelts and refines the spent catalysts within the same process stream as the mined production. The Company both purchases recycling materials for its own account and processes them on behalf of others for a fee.
	The Company’s operations can be significantly affected by risks and uncertainties associated with the mining and recycling industry as well as those specifically related to its operations. One of the most significant risks and uncertainties the Company faces is price volatility of palladium and platinum.
	Additional risks and uncertainties include but are not limited to the following: economic and political events affecting supply and demand for these metals, mineral reserve estimations, environmental restrictions and obligations, governmental regulations, ownership of and access to mineral reserves, stable workforce and increased surety requirements.
	The Company evaluates subsequent events through the date the financial statements are issued. No subsequent events were identified that required additional disclosure through the date of this filing.

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
	PRINCIPLES OF CONSOLIDATION
	The accompanying consolidated financial statements include the accounts of Stillwater Mining Company, its wholly-owned subsidiaries and entities in which it holds a controlling interest (collectively referred to as the “Company”). All intercompany transactions and balances have been eliminated upon consolidation.
	CASH AND CASH EQUIVALENTS
	Cash and cash equivalents consist of all cash balances and all highly liquid investments purchased with an original maturity of three months or less.
	RESTRICTED CASH
	Restricted cash consists of cash equivalents that have been posted as collateral in support of the Company's reclamation liabilities on outstanding letters of credit or other obligations. In the case of collateral for outstanding letters of credit, the restrictions on the balances lapse upon expiration of the letters of credit, which have terms of one year or less. Restricted cash is recorded in Other noncurrent assets on the Company's Consolidated Balance Sheets as the Company anticipates renewing the letters of credit (associated with reclamation obligations) upon expiration. Restricted cash covering other obligations is in the form of Certificates of Deposit which the Company also plans to renew upon expiration.
	INVESTMENTS
	Investment securities at December 31, 2013, and 2012, consist of mutual funds, federal agency notes and commercial paper with stated maturities less than three years. All securities are deemed by management to be available-for-sale and are reported at fair value. Unrealized holding gains and losses on available-for-sale securities are excluded from earnings and are reported as a separate component of other comprehensive income (loss) until realized. Realized gains and losses are based on the carrying value (cost, net of discounts or premiums) of the sold investment and recorded as a component of other income. A decline in the market value of any available-for-sale security below cost that is deemed to be other-than-temporary results in a reduction of the carrying amount of the security to fair value. The impairment is charged to earnings and a new cost basis for the security is established.
	The Company’s long-term investments in several junior exploration companies were originally recorded at cost due to less than 20% equity ownership interest and no significant Company control over the investees. A decline in the market value of these long-term investments that is deemed to be other-than-temporary will result in a reduction of the carrying amount of the investment to fair value. The impairment is charged to earnings and a new cost basis for the investment is established.
	INVENTORIES
	Mined inventories are carried at the lower of current realizable value or average cost taking into consideration the Company’s long-term sales agreements and average unit costs. Production costs include the cost of direct labor and materials, depletion, depreciation and amortization, and overhead costs relating to mining and processing activities. The value of recycled inventories is determined based on the acquisition cost of the recycled material and includes all inventoriable processing costs, including direct labor, direct materials, depreciation and third-party refining costs which relate to the processing activities. Materials and supplies inventories are valued at the lower of average cost or fair market value.
	RECEIVABLES
	Trade receivables and other receivable balances recorded in other current assets are reported at outstanding principal amounts, net of any required allowance for doubtful accounts. Management evaluates the collectability of receivable account balances to determine the allowance, if any. Management considers the other party’s credit risk and financial condition, as well as current and projected economic and market conditions, in determining the amount of the allowance. Receivable balances are written off when management determines that the balance is uncollectable. The Company has written down $0.6 million of the receivable balance at December 31, 2013, due to the uncertainty of ultimate payment. The Company determined that no allowance against its receivable balance at December 31, 2013 and 2012 was necessary.
	MINERAL PROPERTIES AND MINE DEVELOPMENT
	Costs of acquiring mineral properties and mineral rights are capitalized as incurred. Prior to acquiring such mineral properties or mineral rights, the Company makes a preliminary evaluation to determine that the mineral property has significant potential to develop an economic ore body. The time between initial acquisition and full evaluation of a mineral property’s potential is variable and is determined by many factors including its location relative to existing infrastructure, the mineral property’s stage of development, geological controls and relevant metal prices. When it has been determined that proven and probable ore reserves have been established in compliance with the Securities and Exchange Commission's Industry Guide 7, and a determination has been made to proceed toward commercial development, mining development costs incurred to develop the mineral property are capitalized. Mining exploration costs are expensed as incurred. If a mineable ore body is discovered, such costs are amortized when production begins using the units-of-production method based on the quantities of recoverable metal. If no mineable ore body is discovered, such costs are expensed in the period in which it is determined the mineral property has no future economic value. Costs incurred to maintain assets on a standby basis are charged to operations. Costs of abandoned projects are charged to operations upon abandonment.
	Capitalized mine development costs are expenditures incurred to increase existing production, develop new ore bodies or develop mineral property substantially in advance of production. Capitalized mine development costs include a vertical shaft, multiple surface adits and underground infrastructure development including footwall laterals, ramps, rail and transportation, electrical and ventilation systems, shop facilities, material handling areas, ore handling facilities, dewatering and pumping facilities. These expenditures are capitalized and amortized over the life of the mine or over a shorter mining period, depending on the period benefited by those expenditures, using the units-of-production method. The Company utilizes Industry Guide 7 compliant total proven and probable ore reserves, measured in tons, as the basis for determining the life of mine and uses the ore reserves in the immediate and relevant vicinity as the basis for determining the shorter mining period.
	The Company calculates amortization of capitalized mine development costs in any vicinity by applying an amortization rate to the relevant current production. The amortization rates are each based upon a ratio of unamortized capitalized mine development costs to the related ore reserves. Capital development expenditures are added to the unamortized capitalized mine development costs and amortization rates updated as the related assets are placed into service. In the calculation of the amortization rate, changes in ore reserves are accounted for as a prospective change in estimate. Ore reserves and the further benefit of capitalized mine development costs are determined based on management assumptions. Any significant changes in these assumptions, such as a change in the mine plan or a change in estimated proven and probable ore reserves could have a material effect on the expected period of benefit resulting in a potentially significant change in the amortization rate and / or the valuations of related assets. The Company’s proven ore reserves are generally expected to be extracted utilizing its existing mine development infrastructure. Additional capital expenditures will be required to access the Company’s estimated probable ore reserves. These anticipated capital expenditures are not included in the current calculation of depletion, depreciation and amortization.
	Expenditures incurred to sustain existing production and directly access specific ore reserve blocks or stopes provide benefit to ore reserve production over limited periods of time (secondary development) and are charged to operations as incurred. These costs include ramp and stope access excavations from the primary haulage levels (footwall laterals), stope material re-handling / laydown excavations, stope ore and waste pass excavations and chute installations, stope ventilation raise excavations and stope utility and pipe raise excavations.
	PROPERTY, PLANT AND EQUIPMENT
	Plant facilities and equipment are recorded at cost and depreciated using the straight-line method over estimated useful lives ranging from one to fifteen years or, for capital leases, the term of the related leases, if shorter. Maintenance and repairs are charged to cost of revenues as incurred.
	Interest is capitalized on expenditures related to major construction or development projects and is amortized using the same method as the related asset. Interest capitalization is discontinued when the asset is placed into operation or when development and construction cease.
	LEASES
	The Company classifies a lease as either capital or operating. All capital leases are depreciated over the shorter of the useful life of the asset or the lease term.
	ASSET IMPAIRMENT
	The Company reviews and evaluates its long-lived assets, including mineral properties and mine development, for impairment when events or changes in circumstances indicate that the related carrying amounts of its assets may not be recoverable. Impairment is considered to exist if the total estimated future cash flows on an undiscounted basis are less than the carrying amount of the asset. Future cash flows include estimates of recoverable ounces, PGM prices (historical prices or third-party projections of future prices, long-term sales contracts prices, price trends and related factors), production levels and capital and reclamation expenditures, all based on life-of-mine plans and projections. If the assets are impaired, a calculation of fair market value is performed, and if the fair market value is lower than the carrying value of the assets, the assets are reduced to their fair market value.
	Assumptions underlying future cash flows are subject to risks and uncertainties. Any differences between significant assumptions and market conditions such as PGM prices, lower than expected recoverable ounces, and / or the Company’s operating performance could have a material effect on the Company’s determination of ore reserves, or its ability to recover the carrying amounts of its long-lived assets resulting in potential additional impairment charges.
	FAIR VALUE OF FINANCIAL INSTRUMENTS
	The Company’s non-derivative financial instruments consist primarily of cash equivalents, trade receivables, payables, investments, revenue bond debt, convertible debentures and capital lease obligations. The carrying amounts of cash equivalents, trade receivables and payables approximate fair value due to their short maturities. The carrying amounts of investments approximate fair value based on market quotes.
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants. A fair value hierarchy was established which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The fair value hierarchy distinguishes among three levels of inputs that may be utilized when measuring fair value: Level 1 inputs (using quoted prices in active markets for identical assets or liabilities), Level 2 inputs (using external inputs other than Level 1 prices such as quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability) and Level 3 inputs (unobservable inputs supported by little or no market activity and based on internal assumptions used to measure assets and liabilities). The classification of each financial asset or liability within the above hierarchy is determined based on the lowest level input that is significant to the fair value measurement.
	REVENUE RECOGNITION
	Revenue is comprised of Mine Production revenue, PGM Recycling revenue and other sales revenue. Mine Production revenue consists of the sales of palladium and platinum extracted by the Company’s mining operations, including any realized hedging gains or losses, and is reduced by sales discounts associated with long-term sales agreements. Mine Production revenue also consists of the sales of by-products (rhodium, gold, silver, copper and nickel) extracted by mining operations. PGM Recycling revenue consists of the sales of recycled palladium, platinum and rhodium derived from spent catalytic materials, including any unrealized and realized hedging gains or losses. PGM recycling revenue also includes revenue from toll processing. Other sales revenue consists of sales of PGMs that were acquired on the open market for resale.
	Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred either physically or through an irrevocable transfer of metals to customers’ accounts, the price is fixed or determinable, no related obligations remain and collectability is probable. Under the terms of sales contracts and purchase orders received from customers, the Company recognizes revenue when the product is in a refined and saleable form and title passes, which is typically when the product is transferred from the account of the Company to the account of the customer. Under certain of its sales agreements, the Company instructs a third-party refiner to transfer metal from the Company’s account to the customer’s account; at this point, the Company’s account at the third-party refinery is reduced and the purchaser’s account is increased by the number of ounces of metal sold. These transfers are irrevocable and the Company has no further responsibility for the delivery of the metals. Under other sales agreements, physical conveyance occurs by the Company arranging for shipment of metal from the third-party refinery to the purchaser. In these cases, revenue is recognized at the point when title passes contractually to the purchaser. Sales discounts are recognized when the related revenue is recorded. The Company classifies any sales discounts as a reduction in revenue.
	NONCONTROLLING INTEREST
	Noncontrolling interest relates to the sale of a 25% ownership interest in Stillwater Canada Inc during 2012. Noncontrolling interest is classified in the Company's Consolidated Statements of Comprehensive (Loss) Income as part of consolidated net income (loss) and the accumulated amount of noncontrolling interest in the Company's Consolidated Balance Sheets as a component of equity.
	HEDGING PROGRAM
	From time to time, the Company enters into derivative financial instruments, including fixed forwards, cashless put and call option collars and financially settled forwards to manage the effect of changes in the prices of palladium and platinum on the Company’s revenue and to manage interest rate risk. Derivatives are reported on the balance sheet at fair value and, if the derivative is not designated as a hedging instrument, changes in fair value must be recognized in earnings in the period of change. If the derivative is designated as a hedge, and to the extent such hedge is determined to be highly effective, changes in fair value are either (a) offset by the change in fair value of the hedged asset or liability (if applicable) or (b) reported as a component of other comprehensive income (loss) in the period of change, and subsequently recognized in the determination of net income (loss) in the period the offsetting hedged transaction occurs. If an instrument is settled early, any gains or losses are deferred and recognized as adjustments to the revenue recorded for the related hedged production when the transaction related to the original hedge instrument settles.
	Unrealized derivative gains and losses recorded in current and non-current assets and liabilities and amounts recorded in other comprehensive income (loss) and in current period earnings are non-cash items and therefore are taken into account in the preparation of the Company's Consolidated Statements of Cash Flows based on their respective balance sheet classifications.
	RECLAMATION AND ENVIRONMENTAL COSTS
	The fair value of a liability for an asset retirement obligation is recognized in the period in which it is incurred if a reasonable estimate of fair value can be made. The fair value of the liability is added to the carrying amount of the associated asset and this additional carrying amount is depreciated over the life of the asset. The liability is accreted at the end of each period through charges to operating expense. If the obligation is settled for other than the carrying amount of the liability, the Company will recognize a gain or loss on settlement.
	Accounting for reclamation obligations requires management to make estimates for each mining operation of the future costs the Company will incur to complete final reclamation work required to comply with existing laws and regulations. Actual costs incurred in future periods could differ from amounts estimated. Additionally, future changes to environmental laws and regulations could increase the extent of reclamation and remediation work that the Company is required to perform. Any such increases in future costs could materially impact the amounts charged in future periods to operations for reclamation and remediation.
	INCOME TAXES
	The Company determines income taxes using the asset and liability method which results in the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of those assets and liabilities, as well as operating loss and tax credit carryforwards, using enacted tax rates in effect in the years in which the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets and liabilities are recorded on a jurisdictional basis.
	In assessing the realizability of U.S. and foreign deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Each quarter, management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. A valuation allowance has been provided at December 31, 2013, and 2012, for the portion of the Company’s net deferred tax assets for which it is more likely than not that they will not be realized.
	STOCK-BASED COMPENSATION
	Costs resulting from all share-based payment transactions are recognized in the financial statements over the respective vesting periods and determined using a fair-value-based measurement method. The fair values for stock options and other stock-based compensation awards issued to employees are estimated at the date of grant using a Black-Scholes option pricing model.
	EARNINGS (LOSS) PER COMMON SHARE
	Basic earnings (loss) per share attributable to common stockholders is computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted earnings (loss) per share attributable to common stockholders reflects the potential dilution that could occur if the Company’s dilutive outstanding stock options or nonvested shares were exercised and the Company’s convertible debentures were converted. Reported net income (loss) attributable to common stockholders is adjusted for the interest expense net of capitalized interest (including amortization expense of deferred debt and equity fees), the related income tax effect and the income (loss) attributable to the noncontrolling interest in the computation of basic and diluted earnings per share attributable to common stockholders. The Company currently has only one class of equity shares outstanding.
	COMPREHENSIVE INCOME (LOSS)
	Comprehensive income (loss) includes net income (loss), as well as other changes in stockholders’ equity that result from transactions and events other than those with stockholders. The Company’s only significant elements of other comprehensive income in 2013, 2012 and 2011 consisted of unrealized gains and losses related to available-for-sale marketable securities.
	DEBT ISSUANCE COSTS
	Debt issuance costs are capitalized and amortized to interest expense using the effective interest method over the lives of the related debt agreements.
	ADVERTISING COSTS
	Advertising (marketing) costs are expensed as incurred. Advertising expenses were approximately $4.4 million, $10.8 million, and $11.3 million in 2013, 2012 and 2011, respectively.
	USE OF ESTIMATES
	The preparation of the Company’s consolidated financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. The more significant areas requiring the use of management’s estimates relate to mineral reserves, reclamation and environmental obligations, valuation allowance for deferred tax assets, useful lives utilized for depletion, depreciation, amortization and accretion calculations, future cash flows from long-lived assets, fair value of long-lived assets, and fair value of derivatives. Actual results could differ from these estimates.
	During the fourth quarter of 2013, the Company updated its estimates for useful lives of its machinery and equipment; buildings and structural components assets in order to better match the Company's depreciation expense with the periods these assets are expected to generate revenue based on planned and historical operations. The new estimated useful lives were established based on historical replacement data and internal usage data. The Company accounted for this useful life update as a changes in accounting estimate as of December 1, 2013, in accordance with the guidance of ASC Topic 250, Accounting Changes and Error Correction, thereby impacting the quarter in which the change occurred and future quarters. The effect of this change on depreciation was a decrease of $0.5 million for the fourth quarter and year ended December 31, 2013.
	FOREIGN CURRENCY TRANSACTIONS
	The functional currency of the Company’s Canadian and South American subsidiaries is the U.S. dollar. Gains or losses resulting from transactions denominated in Canadian and South American currencies are included in Foreign currency transaction gain, net in the Company's Consolidated Statements of Comprehensive (Loss) Income.
	RECLASSIFICATION
	Prior year amount previously disclosed as restricted cash has been consolidated into other noncurrent assets to conform to the current year presentation on the Company's consolidated balance sheets. Prior year total amount previously disclosed as mineral properties and mine development, net has been separated into two separate components: mineral properties, and mine development, net to conform to the current year presentation on the Company's consolidated balance sheets. Prior year amount previously disclosed as other has been separated into changes in other assets and changes in other liabilities to conform to current year presentation on the Company's consolidated statements of cash flows.

Sales

Sales	12 Months Ended
	Dec. 31, 2013
Sales Revenue, Goods, Net [Abstract]	'
Sales	'
	SALES
	MINE PRODUCTION
	The Company mines and processes ores containing palladium, platinum, rhodium, gold, silver, copper and nickel into intermediate and final products for sale to customers. Palladium, platinum, rhodium, gold and silver are sent to third-party refineries for final processing from where they are sold to a number of consumers and dealers with whom the Company has established trading relationships. Refined PGMs of 99.95% purity (rhodium of 99.9%) in sponge form are transferred upon sale from the Company’s account at third-party refineries to the account of the purchaser. By-products of precious metals are normally sold at market prices to customers, brokers or outside refiners. By-products of copper and nickel are produced by the Company at less than commercial grade, so prices for these metals typically reflect a quality discount. By-product sales are included in revenues from mine production. During 2013, 2012 and 2011, total by-product (copper, nickel, gold, silver and mined rhodium) sales were $27.1 million, $30.6 million and $36.0 million, respectively.
	The Company currently has a one-year market-based platinum supply agreement in place with Tiffany & Co., valid through the end of 2014; at present all other Company sales of mined PGMs are either in the spot market or under mutually agreed short-term extensions of prior supply agreements. The Company is reassessing its marketing strategy in light of increasing demand for PGMs sourced from jurisdictions with secure and stable operating environments. Until this reassessment is completed, the Company believes it should have no difficulty selling PGMs month to month on a spot basis.
	PGM RECYCLING
	The Company purchases spent catalyst materials from third-parties and processes these materials in its facilities in Columbus, Montana to recover palladium, platinum and rhodium for resale. It also accepts recycled material supplied from third-parties on a tolling basis, processing it for a fee and returning the recovered metals to the supplier. The Company has entered into sourcing arrangements for catalyst material with various suppliers. Under these sourcing arrangements as currently structured, the Company may advance cash against a shipment of material shortly before actually receiving the physical shipment. These advances are included in Other current assets on the Company’s Consolidated Balance Sheets until such time as the material has been physically received and title has transferred to the Company. Once the material is physically received and title has transferred, the associated advance is reclassified from Other current assets into Inventories on the Company's Consolidated Balance Sheets. Finance charges collected on advances and inventories prior to being earned are included in Other current liabilities on the Company’s Consolidated Balance Sheets. Finance charges are reclassified from Other current liabilities to Interest income ratably from the time the advance is made until the outturn date of the inventory. The Company recorded write-downs of advances on these recycling inventory purchases of $0.6 million in both 2012 and 2011.
	At the same time the Company purchases recycling material it enters into a fixed forward contract for future delivery of the PGMs contained in the recycled material at a price consistent with the purchase cost of the recycled material. The contract commits the Company to deliver finished metal on a specified date that corresponds to the expected outturn date for the metal from the final refiner. The purpose of this arrangement is to eliminate the Company’s exposure to fluctuations in market prices during processing, while at the same time creating an obligation for the Company to deliver metal at a future point in time that could be subject to operational risks. If the Company is unable to complete the processing of the recycled material by the contractual delivery date, it could either cover its delivery commitments with mine production or purchase finished metal in the open market. If open market purchases are used, the Company bears the risk of any changes in the market price relative to the price stipulated in the delivery contract.
	OTHER
	The Company makes other open market purchases of PGMs from time to time for resale to third-parties. During 2013 and 2012, the Company did not incur any open market purchases but recognized revenue of $1.1 million on PGMs purchased in the open market and re-sold for the year ended December 31, 2011.

Asset_Impairment

Asset Impairment	12 Months Ended
	Dec. 31, 2013
Asset Impairment [Abstract]	'
Asset Impairment	'
	ASSET IMPAIRMENT
	The Company reviews and evaluates its long-lived assets for impairment when events and changes in circumstances indicate that the related carrying amounts of its assets may not be recoverable.
	The Company identified certain events and changes in circumstances that occurred during the third quarter of 2013. Continuing uncertainty in the legal and business climate in Argentina, announcements of reduced investment or the placement on care and maintenance of certain projects in the vicinity of the Company’s Altar mineral property, significant changes in the global mining industry and on-going technical reviews within the Company were all considered in the Company’s assessment. Considering these events individually, and in the aggregate, the Company concluded that a "triggering event" had occurred during the 2013 third quarter requiring it to assess whether its investment in the Altar mineral property was impaired. These adverse changes required the Company to assess whether it could generate cash flows sufficient to recover its investment in the Altar mineral property utilizing scenarios under current consideration by the Company on an undiscounted basis. Based on these scenarios for the Altar mineral property, which have been evolving pursuant to the technical reviews described above, the Company determined that the probability-weighted undiscounted future cash flows from the Altar mineral property were more likely than not, not sufficient to recover the carrying value at September 30, 2013. Having made such determination, the Company undertook an assessment of the fair market value of the property which included examining recent comparable transactions for similar undeveloped mineral properties and market multiples for similar projects. The Company recorded an impairment at September 30, 2013 of $290.4 million (before-tax) in the carrying value of the Altar mineral property in Argentina reducing the carrying value to its estimated fair market value of $102.0 million. There was no change to the carrying value of the Altar property at December 31, 2013.
	In conjunction with information arising from the ongoing Marathon feasibility study, the Company concluded in the fourth quarter of 2013 that unfavorable economics identified in the study constituted a "triggering event" that required determining if the carrying value of the Marathon project is impaired at December 31, 2013. The Company looked at the various potential outcomes of the current work at Marathon and the respective undiscounted cash flows. The result indicated that the current carrying value of Marathon exceeds the expected undiscounted cash flows. As a result, the Company initiated a process, with assistance from a qualified third-party consulting firm, to determine the fair value of Marathon. After considering appropriate comparable transactions that provide an indication of fair value, the Company has written down the carrying value of its Marathon assets at December 31, 2013, from $228.6 million to $57.2 million, with a corresponding $171.4 million charge (before-tax), (mineral properties and mine development of $170.5 million, and depreciable fixed assets of $0.8 million), against fourth quarter 2013 net income. Because the economics at present do not support proceeding with development, the Company no longer is reporting proven and probable ore reserves at Marathon or accounting for Marathon as a development-stage project.

Noncontrolling_Interest

Noncontrolling Interest	12 Months Ended
	Dec. 31, 2013
Noncontrolling Interest [Abstract]	'
Noncontrolling Interest	'
	NONCONTROLLING INTEREST
	In March 2012, the Company entered into an agreement with Mitsubishi Corporation (Mitsubishi) in which a Mitsubishi subsidiary acquired a 25% interest in the Company's wholly-owned subsidiary, Stillwater Canada Inc (SCI) which owns the Marathon PGM-copper project and related properties, for approximately $81.25 million in cash and contributed an additional $13.6 million to satisfy Mitsubishi's portion of the venture's initial cash call. Mitsubishi will be responsible for funding its 25% share of operating, capital and exploration expenditures on the Marathon properties. Mitsubishi will have an option to purchase up to 100% of Marathon's future PGM production under a related supply agreement at a relatively small discount to market. The transaction closed in April 2012. The change in the parent company's equity as a result of the sale of the noncontrolling interest in SCI was an increase to Additional paid in capital of $42.5 million, offset in part by expenses incurred of $1.1 million.
	The noncontrolling interest's share of equity in SCI is reflected as Noncontrolling interest in the Company's Consolidated Balance Sheets and was $19.9 million as of December 31, 2013. The noncontrolling interest balance as of December 31, 2013, reflects Mitsubishi's share of the impairment loss taken on the carrying value of the Marathon assets. The noncontrolling interest portion of the impairment loss was $42.3 million (before-tax).

Derivative_Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments	'
	DERIVATIVE INSTRUMENTS
	The Company uses various derivative financial instruments to manage its exposure to changes in interest rates and PGM market commodity prices. Some of these derivative transactions are designated as hedges. Because the Company hedges only with instruments that have a high correlation with the value of the underlying exposures, changes in the derivatives’ fair value are expected to be offset by changes in the value of the hedged transaction.
	COMMODITY DERIVATIVES
	The Company customarily enters into fixed forward contracts and on occasion enters into financially settled forward contracts to offset the price risk in its PGM recycling activity. From time to time, it also has entered into these types of contracts on portions of its mine production. Under these fixed forward transactions, the Company agrees to deliver a stated quantity of metal on a specific future date at a price stipulated in advance. The Company uses fixed forward transactions primarily to price in advance the metals acquired for processing in its recycling segment. Under financially settled forward transactions, at each settlement date the Company receives the difference between the forward price and the market price if the market price is below the forward price and the Company pays the difference between the forward price and the market price if the market price is above the forward price. These financially settled forward contracts are settled in cash at maturity and do not require physical delivery of metal at settlement. The Company has typically used financially settled forward contracts with third-parties to reduce its exposure to price risk on metal it is obligated to deliver under long-term sales agreements.
	MINE PRODUCTION
	At present, the Company has not entered into derivative instruments to hedge its mined production.
	PGM RECYCLING
	The Company customarily enters into fixed forward sales relating to PGM recycling of catalysts materials. The metals from PGM recycled materials are sold forward at the time of purchase and delivered against the fixed forward contracts when the ounces are recovered. Because the forward price is also used to determine the acquisition price, this arrangement significantly reduces exposure to PGM price volatility. The Company believes such transactions qualify for the exception to hedge accounting treatment and so has elected to account for these transactions as normal purchases and normal sales.
	All of the fixed forward sales contracts open at December 31, 2013, will settle at various periods through May 2014. The Company has credit agreements with its major trading partners that provide for margin deposits in the event that forward prices for metals exceed the Company’s hedged prices by a predetermined margin limit. As of December 31, 2013, and 2012, no margin deposits were outstanding or due.
	On occasion, the Company has entered into financially settled forward contracts on its recycled materials. Such contracts are utilized when the Company wishes to establish a firm forward price for recycled metal on a specific future date. No financially settled forward contracts were entered into during the years ended December 31, 2013, and 2012. The Company generally has not designated these contracts as cash flow hedges, so they are marked to market at the end of each accounting period. The change in the fair value of the derivatives is reflected in the Company's Consolidated Statements of Comprehensive (Loss) Income.
	The following is a summary of the Company’s commodity derivatives as of December 31, 2013:
	PGM Recycling:	Platinum			Palladium			Rhodium
	Fixed Forward Contracts
	Settlement Period	Ounces	Average Price		Ounces	Average Price		Ounces	Average Price
	First Quarter 2014	26,997	$	1,409	46,043	$	728	7,277	$	951
	Second Quarter 2014	1,761	$	1,356	1,696	$	721	988	$	899

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-Based Compensation	'
	SHARE-BASED COMPENSATION
	STOCK PLANS
	The Company sponsors stock option plans (the “Plans”) that enable the Company to grant stock options or other equity based compensation to employees and non-employee directors. Effective March 2011, the Company ceased offering stock options as incentive compensation to employees and non-employee directors and began to issue only cash awards or restricted stock units in lieu of stock options. The Company continues to have previously issued stock options that remain outstanding under three separate plans: the 1994 Incentive Plan (amended by the 1998 Incentive Plan), the General Employee Plan and the 2004 Equity Incentive Plan. In April 2012, stockholders approved the 2012 Equity Incentive Plan. At inception of the plans, approximately 16.4 million shares of common stock were authorized under the Plans, including approximately 5.0 million, 5.2 million, 1.4 million and 4.8 million authorized shares for the 2012 Equity Incentive Plan, 2004 Equity Incentive Plan, the General Employee Plan and the 1994 Incentive Plan (as amended by the 1998 Incentive Plan), respectively. The 1998 Incentive Plan and the General Plan have been terminated and no additional options, shares or units may be issued under these two terminated plans. Approximately 5.0 million shares were available and reserved for grant under the 2012 Equity Incentive Plan as of December 31, 2013.
	The Compensation Committee of the Company’s Board of Directors administers the Plans and determines the type of equity awards to be issued, the exercise period, vesting period and all other terms of instruments issued under the Plans. Employees’ options and restricted stock units vest in equal annual installments over a three year period after date of grant. Options expire ten years after the date of grant. Certain of the Company's equity incentive plans and award agreements contain "change in control" provisions which provide that, among other "triggering events", a "change in control" occurs if following the election of new directors to the Board of Directors, a majority of the members of the Board of Directors are not considered "incumbent directors."
	On May 7, 2013, the Company announced the election of four new directors to the Company's Board of Directors. The election resulted in four incumbent directors being retained on the board and four new directors being elected to the board. This four / four split constituted a "change in control" event under the 2004 and 2012 Equity Plans. As a result of this change in control, all unvested stock options and unvested restricted stock units that had previously been granted under the 2004 and 2012 Equity Plans (excluding those unrestricted stock units granted under the 2004 Equity Plan to individuals eligible for the Company's 409A deferral plans) became fully vested, effective May 7, 2013.
	On June 7, 2013, Francis R. McAllister, the Company's former Chief Executive Officer, announced his retirement from the Company. At the time of his retirement, Mr. McAllister was a member of the Company's Board of Directors. His retirement constituted another "change in control" event that resulted in the accelerated vesting of all remaining unvested restricted stock that had been granted through the date of Mr. McAllister's retirement.
	NONVESTED SHARES
	Nonvested share activity during 2013, 2012 and 2011, is detailed in the following table:
	Year ended December 31,	Nonvested		Weighted-
		Shares		Average
				Grant-
				Date Fair
				Value
	Nonvested shares at December 31, 2010	1,563,886		$	7.51
	Granted	369,417		22.49
	Vested	(429,425	)	15.1
	Forfeited	(1,267	)	18.78
	Nonvested shares at December 31, 2011	1,502,611		$	10.95
	Granted	653,712		13.12
	Vested	(927,228	)	7.98
	Forfeited	(79,762	)	13.8
	Nonvested shares at December 31, 2012	1,149,333		$	14.38
	Granted	544,122		13.64
	Vested (1)	(1,661,783	)	14.19
	Forfeited	(615	)	13.99
	Nonvested shares at December 31, 2013	31,057		$	11.55
	(1) Pursuant to the terms of the Company's Equity Plans, the change in control that occurred in the second quarter of 2013 resulted in all outstanding nonvested shares granted under those Equity Plans immediately becoming fully vested.
	Compensation expense for the year ended December 31, 2013, totaled $13.7 million, of which $4.6 million is included in General and administrative in the Company's Consolidated Statements of Comprehensive (Loss) Income and $9.1 million (non-cash charge) resulting from the triggering of the change in control provisions under the 2004 and 2012 Equity Incentive Plans is recorded as Accelerated equity based compensation expense in the Company's Consolidated Statements of Comprehensive (Loss) Income. Compensation expense, included within General and administrative in the Company's Consolidated Statements of Comprehensive (Loss) Income related to grants of nonvested shares for years ended 2012 and 2011 was $8.2 million and $6.4 million, respectively.
	Total compensation expense related to nonvested shares at December 31, 2013, is currently expected to be approximately $119,100, $119,400 and $106,400 for the years 2014, 2015 and 2016, respectively.
	DEFERRAL PLANS
	The Company's Non-Employee Directors’ Deferral Plan, allows non-employee directors to defer all or any portion of the compensation received as directors, in accordance with the provisions of Section 409A of the Internal Revenue Code and associated Treasury regulations. All amounts deferred under this plan are fully vested, and each participant elects the deferral period and form of the compensation (Company common stock or cash). The plan provides for a Company matching contribution equal to 20% of the participant’s deferred stock amount. Compensation expense that was deferred in common stock related to the Non-Employee Directors’ Deferral Plan was $64,200, $83,400 and $69,150 in 2013, 2012 and 2011, respectively. The Company match was made in Company common stock. There were no cash deferrals related to the Non-Employee Directors’ Deferral Plan in 2013 and 2012.
	The Company's Nonqualified Deferred Compensation Plan, allows certain key personnel of the Company to defer up to 60% of their salaries; up to 100% of other cash compensation and up to 100% of their restricted stock units upon vesting in accordance with the provisions of Section 409A of the Internal Revenue Code and associated Treasury regulations. All amounts deferred under this plan are fully vested, and each participant elects the deferral period and form of the compensation (Company common stock or cash). For each Plan year, the Company matches the amount of compensation deferred during that year up to a maximum of 8% of the participant’s total compensation for the calendar year. Compensation expense deferred in cash was $203,000, $342,000 and $248,800 in 2013, 2012 and 2011, respectively.
	STOCK OPTIONS
	Historically, the Company recognized compensation expense associated with its stock option grants based on their fair market value on the date of grant as determined using a Black-Scholes option pricing model. As discussed above, the change in control that occurred in the second quarter of 2013 resulted in all outstanding, unvested stock options granted under the 2004 and 2012 Equity Plans becoming fully vested. Unless vesting is accelerated due to a change in control or other event, the Company recognizes stock option expense ratably over the vesting period of the options. If options are canceled or forfeited prior to vesting, the Company stops recognizing the related expense effective with the date of forfeiture. However, because of the accelerated vesting of all outstanding stock options in the second quarter of 2013, the Company was required to recognize the remaining expense of such vesting immediately.
	Because all outstanding, unvested stock options vested in the second quarter of 2013, there was no compensation expense associated with stock option grants recorded in the second half of 2013. Compensation expense related to the fair value of stock options for the periods ended December 31, 2013, and 2012 was $41,400 and $96,870, respectively. The compensation expense is recorded in General and administrative in the Company's Consolidated Statements of Comprehensive (Loss) Income.
	The Company received approximately $0.1 million, less than $0.1 million and $0.8 million in cash from the exercise of stock options in 2013, 2012 and 2011, respectively.
	The fair value for options granted in 2011 was estimated at the date of grant using a Black-Scholes option pricing model with the following weighted-average assumptions:
	Year ended December 31,	2011
	Weighted average expected lives (years)	3.5
	Interest rate	0.8	%
	Volatility	67	%
	Dividend yield	—
	Stock option activity for the years ended December 31, 2013, 2012 and 2011, is summarized as follows (excluding the effect of nonvested shares):
	Year Ended December 31,	Shares		Weighted				Weighted-
				Average				Average
				Exercise				Grant-
				Price				Date Fair
								Value
	Options outstanding at December 31, 2010	595,939		$	20.54
	Options exercisable at December 31, 2010	530,724		21.32
	2011 Activity
	Options granted	103,479		6.87				$	5.14
	Options exercised	(52,131	)	15.1
	Options canceled/forfeited	(155,175	)	33.25
	Options outstanding at December 31, 2011	492,112		$	14.23
	Options exercisable at December 31, 2011	454,966		14.06
	2012 Activity
	Options granted	—		—
	Options exercised	(16,552	)	2.61
	Options canceled/forfeited	(233,041	)	18.86
	Options outstanding at December 31, 2012	242,519		$	10.57
	Options exercisable at December 31, 2012	224,933		10.08
	2013 Activity
Options granted	—		—
Options exercised	(25,471	)	5.02
Options canceled/forfeited	(17,757	)	6.07
Options outstanding at December 31, 2013	199,291		$	11.68
Options exercisable at December 31, 2013	199,291		11.68
The total intrinsic value of stock options exercised during each of the years ended December 31, 2013, and 2012 was $0.2 million and for the year ended December 31, 2011, the total intrinsic value of stock options exercised was $0.4 million. At December 31, 2013, the total intrinsic value was $0.5 million for both stock options outstanding and exercisable. The Company issued 96,154 replacement options to Peregrine Metals Ltd. optionholders upon closing the acquisition of Peregrine Metals Ltd. in the fourth quarter of 2011. These replacement options were included as part of the total consideration paid.
The following table summarizes information for outstanding and exercisable options as of December 31, 2013:
			Options Outstanding						Options Exercisable
Range of Exercise	Number		Weighted Average		Weighted				Number	Weighted
Price	Outstanding		Remaining		Average				Exercisable	Average
			Contract		Exercise					Exercise
			Life		Price					Price
$  3.96 - $  4.66	1,292		4.8		$	4.3			1,292	$	4.3
$  4.67 - $  9.33	80,039		2.1		$	6.92			80,039	$	6.92
$  9.34 - $13.99	42,159		3.8		$	12.04			42,159	$	12.04
$14.00 - $18.65	53,151		1.8		$	15.1			53,151	$	15.1
$18.66 - $23.31	21,050		6.5		$	19.95			21,050	$	19.95
$23.32 - $24.55	1,600		7.1		$	24.41			1,600	$	24.41
	199,291		2.9		$	11.68			199,291	$	11.68
A summary of the status of the Company’s nonvested stock options as of December 31, 2013, and changes during the year then ended, is presented below:
Nonvested Options	Options		Weighted-
			Average
			Grant-
			Date Fair
			Value
Nonvested options at January 1, 2013	17,586		$	8.19
Options vested (1)	(17,586	)	8.19
Nonvested options at December 31, 2013	—
(1) Pursuant to the terms of the Company's Equity Plans, the change in control that occurred in the second quarter of 2013 resulted in all outstanding nonvested shares granted under those Equity Plans immediately becoming fully vested.
EMPLOYEE BENEFIT PLANS
The Company has two savings plans, which qualify under section 401(k) of the U.S. Internal Revenue Code, covering essentially all non-bargaining and bargaining employees. Employees may elect to contribute up to 60% of their eligible compensation, subject to the Employee Retirement Income Security Act of 1974 (ERISA) limitations. The Company is required to make matching contributions equal to 100% of the employee’s contribution up to 8% of the employee’s compensation. Matching contributions are made with common stock of the Company. During 2013, 2012 and 2011, the Company issued approximately 0.9 million, 0.7 million and 0.4 million shares of common stock, respectively, with a market value on the respective grant dates of $10.3 million, $7.9 million and $5.6 million, respectively, to match employees’ contributions. The Company made no cash contributions to the plans in 2013, 2012 and 2011.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	INCOME TAXES
	The components of the Company’s deferred income tax liabilities (assets) are comprised of the following temporary differences and carryforwards at December 31, 2013, and 2012.
	December 31, (In thousands)	2013			2012
	Mine development and mineral interests-US	$	105,366		$	112,867
	Mine development and mineral interests-Canada	(1,234		)	49,758
	Mineral interests-South America	27,333			111,961
	Long-term debt	49,936			56,281
	Total deferred tax liabilities	$	181,401		$	330,867
	Noncurrent liabilities	(9,928		)	(12,644		)
	Property and equipment	(18,502		)	(14,214		)
	Current liabilities	(20,696		)	(20,243		)
	Long-term investments	(3,108		)	(2,372		)
	Inventory	(1,972		)	(1,061		)
	AMT credit and other carryforwards	(17,021		)	(5,989		)
	Exploration	(5,391		)	(4,815		)
	Net operating loss and other carryforwards	(67,856		)	(109,556		)
	Total deferred tax assets	$	(144,474	)	$	(170,894	)
	Valuation allowance	20,685			18,525
	Net deferred tax assets	(123,789		)	(152,369		)
	Net deferred tax liabilities	$	57,612		$	178,498
	In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. The Company provided a valuation allowance in 2013 and 2012 to reflect the estimated amount of deferred tax assets which may not be realized, which principally relate to foreign and state net operating losses, and certain tax credits. The NOLs and other carryforwards for 2013 above represent $56.1 million from U.S. operations and $11.8 million from foreign operations. The NOLs for 2012 above represent $99.3 million from U.S. operations and $10.3 million from foreign operations.
	Reconciliation of the income tax provision at the applicable statutory income tax rates to the effective rate is as follows:
	Year ended December 31, (In thousands)	2013			2012			2011
	(Loss) income before income taxes	$	(395,726	)	$	50,377		$	155,530
	Income tax (benefit) provision at statutory rates	(138,504		)	18,302			53,648
	State income tax expense, net of federal benefit	3,995			4,173			6,898
	Percentage depletion	(8,786		)	(4,985		)	(37,163		)
	Foreign currency transaction gain, net	31,605			(5,304		)	(1,131		)
	NOL utilization adjustment	—			(4,277		)	—
	Compensation related adjustment	359			2,026			1,700
	Change in valuation allowance	5,595			(14,514		)	(13,937		)
	Return-to-provision	1,097			—			—
	Foreign rate differential	8,895			—			—
	Other	2,091			540			1,220
	Net income tax (benefit) provision	$	(93,653	)	$	(4,039	)	$	11,235
	At December 31, 2013, the Company had approximately $195.5 million of regular federal tax net operating loss carryforwards in the U.S. expiring from 2019 through 2028. Usage of $100.5 million of these net operating losses is limited to approximately $10.2 million annually as a result of the change in control of the Company that occurred in connection with the Norilsk Nickel transaction in 2003. Usage of $95.0 million of these net operating losses is limited to approximately $77.7 million annually, exclusive of any net realized built-in gains, as a result of the exit of Norilsk Nickel in 2010. The Company had $15.7 million of alternative minimum tax credit carryforwards which will not expire and $1.2 million in general business credits expiring during 2031 to 2033. The Company had approximately $2.9 million of state tax net operating loss carryforwards expiring during 2020 through 2029. The Company also had $44.8 million of foreign net operating loss carryforwards, the expiration of which varies by foreign jurisdiction.
	Cash payments for state income taxes were made in 2013 in the amount of $0.1 million related to the tax year 2012 and no state payments were made in 2012 or 2011. A U.S. federal extension tax payment in the amount of $5.2 million was made in 2013, which is related to 2012. A U.S. federal extension tax payment in the amount of $4.8 million was made in 2012, which was related to 2011. The Company had a net tax receivable of $0.6 million relating to current and prior year anticipated U.S. and state tax filings. The deferred foreign tax expense is a non-cash expense related to the Argentina impairment.
	The Company’s policy is to recognize interest and penalties on unrecognized tax benefits in Income tax benefit (provision) in the Company's Consolidated Statements of Comprehensive (Loss) Income. The interest and penalties accrued at December 31, 2013, and 2012, were $2.1 million and less than $0.1 million, respectively. There was no interest or penalties of this nature for the year ended December 31, 2011. The Company has included expense of $1.4 million and $0.2 million for unrecognized tax benefit for the years ended December 31, 2013, and 2012, respectively. The tax years subject to examination by the taxing authorities are the years ending December 31, 2012, 2011 and 2010. Although, net operating loss and credit carryforwards from all years are subject to examination and adjustments for three years following the year in which utilized.
	The income tax (benefit) provision is comprised of the following:
	Year ended December 31, (In thousands)	2013			2012			2011
	Current
	Federal	$	9,740		$	1,721		$	11,235
	State	5,152			200			—
	Current income tax	$	14,892		$	1,921		$	11,235
	Deferred
	Federal	5,278			—			—
	State	252			—			—
	Foreign	(114,075		)	(5,960		)	—
	Deferred income tax benefit	(108,545		)	(5,960		)	—
	Income tax (benefit) provision	$	(93,653	)	$	(4,039	)	$	11,235
	The components of (loss) income before income tax benefit (provision) by tax jurisdiction for the years ended December 31, 2013, 2012 and 2011 were as follows:
	(In millions)	2013			2012			2011
	United States	$	61,671		$	60,166		$	157,215
	Foreign	(457,397		)	(9,789		)	(1,685		)
	(Loss) income before income tax benefit (provision)	$	(395,726	)	$	50,377		$	155,530

Comprehensive_GainLoss

Comprehensive Gain/(Loss)	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Comprehensive Gain/(Loss)	'
	COMPREHENSIVE GAIN/(LOSS)
	Comprehensive gain/(loss) consists of earnings items and other gains and losses affecting stockholders’ equity that are excluded from current net income. As of December 31, 2013, 2012 and 2011, such items consisted of unrealized gains / losses on available-for-sale marketable securities.
	The following summary sets forth the changes in Accumulated other comprehensive income (loss) during 2013, 2012 and 2011:
	(In thousands)	Available-for-Sale
		Securities
	Balance at December 31, 2010	$	(852	)
	Change in value	(109		)
	Comprehensive loss	$	(109	)
	Balance at December 31, 2011	$	(961	)
	Change in value	862
	Comprehensive gain	$	862
	Balance at December 31, 2012	$	(99	)
	Change in value	105
	Comprehensive gain	$	105
	Balance at December 31, 2013	$	6

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	SEGMENT INFORMATION
	The Company operates five reportable business segments: Mine Production, PGM Recycling, Canadian Properties, South American Properties and All Other. These segments are managed separately based on fundamental differences in their operations and geographic separation.
	The Mine Production segment consists of two business components: the Stillwater Mine and the East Boulder Mine. The Mine Production segment is engaged in the development, extraction, processing and refining of PGMs. The Company sells PGMs from mine production under short-term and long-term sales agreements and in open PGM markets. The financial results for the Stillwater Mine and the East Boulder Mine have been aggregated, as both have similar products, processes, customers, distribution methods and economic characteristics.
	The PGM Recycling segment is engaged in the recycling of spent catalyst material to recover the PGMs contained in the material. The Company purchases the majority of catalyst material processed by the PGM Recycling segment from third-party suppliers for its own account and sells the recovered metals directly, and it also accepts catalyst material supplied from third-parties on a tolling basis, processing it for a fee and returning the recovered metals to the supplier. The Company allocates costs of the Company's smelting and base metal refining facilities to both the Mine Production segment and to the PGM Recycling segment for internal and segment reporting purposes because these facilities support the PGM extraction requirements of both business segments.
	The Canadian Properties segment consists of the Marathon PGM assets (which consist primarily of the Marathon project mineral property) and the Coldwell Complex exploration mineral properties. The Marathon project mineral property is a large PGM and copper deposit located near the town of Marathon, Ontario, Canada. The Coldwell Complex exploration mineral properties are located adjacent to the Marathon property. As of December 31, 2013, the Company is no longer reporting proven and probable ore reserves at Marathon or accounting for Marathon as a development-stage project. The Company will cease to capitalize future project expenditures incurred in connection with Marathon. See "Note 4 - Asset Impairment" for more information.
	The South American Properties segment consists of the Peregrine Metals Ltd. assets. The principal Peregrine property is the Altar project, a copper-gold resource, located in the San Juan province of Argentina. The Altar project is currently in the exploration stage. Financial information for this segment consists of total asset values, general and administrative costs and exploration costs. In the third quarter of 2013, the Company took an impairment charge of $290.4 million on the Peregrine properties. See "Note 4 - Asset Impairment" for more information.
	The All Other group primarily consists of assets, including investments, revenues, and expenses of various corporate and support functions and, historically, marketing expenditures related to promoting palladium.
	The Company evaluates performance and allocates resources based on income or loss before income taxes.
	The following financial information relates to the Company’s business segments:
	(In thousands)	Mine		PGM		Canadian			South			All			Total
		Production		Recycling		Properties			American			Other
	Year ended December 31, 2013								Properties
	Revenues	$	478,918	$	560,588	$	—		$	—		$	—		$	1,039,506
	Depletion, depreciation and amortization	$	58,201	$	1,116	$	—		$	—		$	—		$	59,317
	General and administrative expenses	$	—	$	—	$	1,112		$	2,549		$	38,324		$	41,985
	Interest income	$	—	$	3,375	$	20		$	184		$	902		$	4,481
	Interest expense	$	—	$	—	$	—		$	—		$	22,957		$	22,957
	Income (loss) before impairment charge and income taxes	$	106,122	$	35,463	$	(4,255	)	$	8,845		$	(80,146	)	$	66,029
	Impairment charge	$	—	$	—	$	171,338		$	290,417		$	—		$	461,755
	Income (loss) after impairment charge, before income taxes	$	106,122	$	35,463	$	(175,593	)	$	(281,572	)	$	(80,146	)	$	(395,726	)
	Capital expenditures	$	108,527	$	330	$	12,380		$	101		$	7,691		$	129,029
	Total assets	$	553,153	$	80,555	$	83,800		$	109,960		$	519,212		$	1,346,680
	(In thousands)	Mine		PGM		Canadian			South			All			Total
		Production		Recycling		Properties			American			Other
	Year ended December 31, 2012								Properties
	Revenues	$	455,426	$	344,818	$	—		$	—		$	—		$	800,244
	Depletion, depreciation and amortization	$	56,960	$	1,055	$	—		$	—		$	—		$	58,015
	General and administrative expenses	$	—	$	—	$	3,785		$	3,334		$	33,829		$	40,948
	Interest income	$	—	$	2,293	$	29		$	208		$	(205	)	$	2,325
	Interest expense	$	—	$	—	$	12		$	—		$	10,908		$	10,920
	Income (loss) before income taxes	$	109,255	$	10,452	$	(7,344	)	$	(2,254	)	$	(59,732	)	$	50,377
	Capital expenditures	$	96,307	$	353	$	8,319		$	18		$	7,074		$	112,071
	Total assets	$	470,251	$	92,899	$	258,918		$	412,836		$	655,859		$	1,890,763
	(In thousands)	Mine		PGM		Canadian			South			All			Total
		Production		Recycling		Properties			American			Other
	Year ended December 31, 2011								Properties
	Revenues	$	528,007	$	376,820	$	—		$	—		$	1,142		$	905,969
	Depletion, depreciation and amortization	$	61,312	$	1,066	$	—		$	—		$	—		$	62,378
	General and administrative expenses	$	—	$	—	$	2,511		$	2,163		$	37,398		$	42,072
	Interest income	$	—	$	2,228	$	—		$	66		$	1,280		$	3,574
	Interest expense	$	—	$	—	$	—		$	—		$	6,548		$	6,548
	Income (loss) before income taxes	$	197,250	$	18,816	$	(2,576	)	$	(2,097	)	$	(55,863	)	$	155,530
	Capital expenditures	$	88,056	$	243	$	13,470		$	63		$	108		$	101,940
	Total assets	$	416,740	$	70,901	$	196,706		$	440,942		$	202,035		$	1,327,324

Investments

Investments	12 Months Ended
	Dec. 31, 2013
Investments [Abstract]	'
Investments	'
	INVESTMENTS
	The Company classifies the marketable securities in which it invests as available-for-sale securities. These securities are measured at fair market value in the financial statements with unrealized gains or losses recorded in Other comprehensive income (loss) in the Company's Consolidated Statements of Comprehensive (Loss) Income. At the time the securities are sold or otherwise disposed of, gross realized gains and losses are included in Net (loss) income. Gross realized gains and losses are based on the carrying value (cost, net of discounts or premiums) of the sold investment. The Company adopted ASU 2013-02 Reporting Amounts Reclassified out of Other Comprehensive Income as of January 1, 2013. The amounts reclassified out of Other comprehensive income (loss) during the periods ended December 31, 2013, and 2012 were insignificant. All of the marketable securities amounts are available to satisfy current obligations.
	The amortized cost, gross unrealized gains, gross unrealized losses, and fair market value of available-for-sale investment securities by major security type and class of security at December 31, are as follows:
	(In thousands)	Amortized		Gross		Gross			Fair
		Cost		unrealized		unrealized			market
				gains		losses			value
	2013
	Federal agency notes	$	97,509	$	76	$	—		$	97,585
	Commercial paper	112,063		10		(320		)	111,753
	Mutual funds	359		245		—			604
	Total	$	209,931	$	331	$	(320	)	$	209,942
	2012
	Federal agency notes	$	124,682	$	37	$	(4	)	$	124,715
	Commercial paper	137,661		3		(396		)	137,268
	Mutual funds	1,556		261		—			1,817
	Total	$	263,899	$	301	$	(400	)	$	263,800
	The mutual funds included in the investment table above are included in Other noncurrent assets on the Company's Consolidated Balance Sheets.
	The maturities of available-for-sale securities at December 31, 2013, are as follows:
	(In thousands)	Amortized cost		Fair market value
	Federal agency notes
	Due in one year or less	$	48,359	$	48,401
	Due after one year through three years	49,150		49,184
	Total	$	97,509	$	97,585
	Commercial paper
	Due in one year or less	$	92,142	$	91,871
	Due after one year through three years	19,921		19,882
	Total	$	112,063	$	111,753
	The Company has long-term investments in several Canadian junior exploration companies, recorded on the balance sheet at cost. The Company determined that its long-term investments were other than temporarily impaired and recorded a loss of $1.9 million and $2.6 million for the years ended December 31, 2013, and 2012, respectively. At December 31, 2013, these long-term investments totaled $1.0 million and are recorded in Other noncurrent assets on the Company's Consolidated Balance Sheets.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2013
Inventory Disclosure [Abstract]	'
Inventories	'
	INVENTORIES
	For purposes of inventory accounting, the market value of inventory is generally deemed equal to the Company’s current cost of replacing the inventory, provided that: (1) the market value of the inventory may not exceed the estimated selling price of such inventory in the ordinary course of business less reasonably predictable costs of completion and disposal, and (2) the market value may not be less than net realizable value reduced by an allowance for a normal profit margin. No reduction to inventory value was necessary during 2013 and 2012.
	The costs of mined PGM inventories as of any date are determined based on combined production costs per ounce and include all inventoriable production costs, including direct labor, direct materials, depletion, depreciation and amortization and other overhead costs relating to mining and processing activities incurred as of such date.
	The costs of recycled PGM inventories as of any date are determined based on the acquisition cost of the recycled material and include all inventoriable processing costs, including direct labor, direct materials, depreciation and third-party refining costs which relate to the processing activities incurred as of such date.
	Inventories reflected in the accompanying balance sheets at December 31, consisted of the following:
	(In thousands)	2013		2012
	Metals inventory
	Raw ore	$	4,638	$	3,505
	Concentrate and in-process	67,251		51,498
	Finished goods	60,100		74,942
		$	131,989	$	129,945
	Materials and supplies	26,661		23,263
	Total inventory	$	158,650	$	153,208
	The Company also holds in its possession, but does not reflect in inventory, materials it processes on a toll basis for customers until the tolled material is transported to a third-party refiner.

Earnings_Per_Common_Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings Per Common Share	'
	EARNINGS PER COMMON SHARE
	Basic (loss) earnings per share attributable to common stockholders is computed by dividing net earnings available to common stockholders by the weighted average number of common shares outstanding during the period. Diluted (loss) earnings per share attributable to common stockholders reflects the potential dilution that could occur if the Company’s dilutive outstanding stock options or nonvested shares were exercised or vested and the Company’s convertible debt was converted. For the purposes of calculating earnings per share attributable to common stockholders, reported consolidated net (loss) income attributable to common stockholders was adjusted for the interest expense, net of capitalized interest (including amortization expense of deferred debt fees), the related income tax effect and the income (loss) attributable to the noncontrolling interest in the computation of basic and diluted earnings per share attributable to common stockholders. The Company currently has only one class of equity shares outstanding.
	Outstanding options to purchase 45,269 weighted shares of common stock were excluded from the computation of diluted earnings (loss) per share attributable to common stockholders in 2013 because the Company reported a net loss and therefore the effect would have been antidilutive. Outstanding options to purchase 121,569 and 273,965 weighted shares of common stock were excluded from the computation of diluted earnings per share attributable to common stockholders for 2012 and 2011, respectively, because the market price at the end of the period was lower than the exercise price, and therefore the effect would have been antidilutive.
	The was no effect of outstanding nonvested shares on diluted weighted average shares outstanding in 2013 because the Company reported a net loss and inclusion of any of these shares would have reduced the net loss per share amounts. The effect of outstanding nonvested shares was to increase diluted weighted average shares outstanding by 762,060 and 957,604 shares in 2012 and 2011, respectively.
	Reconciliations showing the computation of basic and diluted shares and the related impact on income for the years ended December 31, 2012 and 2011 are shown in the following table:
		Year Ended					Year Ended
		31-Dec-12					31-Dec-11
	(In thousands, except per share amounts)	Income (Numerator)		Weighted Average Shares (Denominator)	Per Share Amount		Income		Weighted	Per
							(Numerator)		Average	Share
									Shares	Amount
									(Denominator)
	Basic EPS
	Net income attributable to common stockholders	$	55,045	116,162	$	0.47	$	144,295	105,846	$	1.36
	Effect of Dilutive Securities
	Stock options	—		58			—		60
	Nonvested shares	—		762			—		958
	1.875% Convertible debentures, net of tax	2,355		7,082			3,651		7,082
	1.75% Convertible debentures, net of tax	2,774		7,377			—		—
	Diluted EPS
	Net income attributable to common stockholders and assumed conversions	$	60,174	131,441	$	0.46	$	147,946	113,946	$	1.3

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
	1.875% CONVERTIBLE DEBENTURES
	In March 2008, the Company issued and sold $181.5 million of 1.875% aggregate principal amount senior unsecured convertible debentures due March 15, 2028, with interest payable semiannually. Each $1,000 principal amount of 1.875% debentures is initially convertible, at the option of the holders, into approximately 42.5351 shares of the Company’s common stock, at any time prior to the maturity date. The conversion rate is subject to certain adjustments, but will not be adjusted for accrued interest or any unpaid interest. The conversion rate initially represents a conversion price of $23.51 per share.
	In October 2009, the Company exchanged $15.0 million face amount of the 1.875% debentures for 1.84 million shares of the Company’s common stock, leaving $166.5 million face value of the debentures outstanding at December 31, 2009. In March 2013, the holders of $164.3 million of the 1.875% debentures exercised their option to require the Company to redeem their debentures at face value. Holders of the remaining $2.2 million of outstanding 1.875% debentures may require the Company to redeem their 1.875% debentures at face value on March 15, 2018 or March 15, 2023, or at any time before March 15, 2028 upon the occurrence of certain events including a change in control. Effective as of March 22, 2013, the Company has the right at its discretion to redeem the remaining $2.2 million of outstanding 1.875% debentures for cash at any time prior to maturity. The outstanding balance of $2.2 million is reported as a long-term debt obligation as of December 31, 2013.
	Amortization expense related to the issuance costs of the 1.875% debentures was $0.2 million for the year ended December 31, 2013, and $0.9 million for the years ended December 31, 2012 and 2011. Interest expense on the 1.875% debentures was $0.3 million for the year ended December 31, 2013, and $3.1 million for the years ended December 31, 2012 and 2011. The Company made cash payments of $1.6 million for interest on the 1.875% debentures for the year ended December 31, 2013, and $3.1 million for the years ended December 31, 2012 and 2011.
	1.75% CONVERTIBLE DEBENTURES
	In October 2012, the Company issued $396.75 million of 1.75% senior unsecured convertible debentures, due October 15, 2032. Each $1,000 principal amount of these 1.75% debentures is initially convertible, under certain circumstances and during certain periods, into 60.4961 shares (subject to customary anti-dilution adjustments) of the Company's common stock, which represents an initial conversion price of $16.53 per share. The 1.75% debentures also include an embedded conversion enhancement feature that is equivalent to including with each debenture a warrant initially exercisable for 30.2481 shares initially at $16.53 per share (also subject to customary anti-dilution adjustments). The Company, at its election, may settle conversions of the 1.75% debentures in cash, shares of its common stock or any combination of cash and shares of its common stock. Holders have the right to redeem their 1.75% debentures at face value plus accrued and unpaid interest on October 15, of each of 2019, 2024, 2029, and upon the occurrence of certain corporate events. The Company will have the right to call the 1.75% debentures at any time on or after October 20, 2019.
	The 1.75% debentures were bifurcated under U.S. GAAP into separate debt and equity components, and reflect an effective maturity (to the first optional redemption date) of seven years. The residual amount of $141.6 million recorded in equity is treated for accounting purposes as additional debt discount and accreted as an additional non-cash interest charge to earnings over the expected life. Debt and equity issuance costs totaling approximately $12.4 million were deducted from the gross proceeds of the offering of the 1.75% debentures and the debt portion is being amortized ratably over seven years. Net proceeds of $384.3 million from the offering were used in part to retire $164.3 million of the Company's 1.875% convertible debentures upon their redemption in March 2013 with the remainder being used for general corporate purposes.
	The 1.75% debentures have an effective interest rate of 8.50% and a stated interest rate of 1.75% with interest paid semi-annually. The balance outstanding for the year ended December 31, 2013, was $274.0 million, which is net of unamortized discount of $122.8 million.
	Amortization of debt issuance costs related to the issuance of the 1.75% debentures was $1.1 million and $0.2 million for the periods ended December 31, 2013, and 2012, respectively. Interest expense related to the 1.75% debentures was $18.3 million and $4.5 million for the periods ended December 31, 2013, and 2012, respectively. The Company made $6.9 million in interest payments on the 1.75% debentures during the period ended December 31, 2013. The Company made no cash payments for the period ended December 31, 2012.
	EXEMPT FACILITY REVENUE BONDS
	During 2000, the Company completed a $30.0 million offering of Exempt Facility Revenue Bonds, Series 2000, through the State of Montana Board of Investments. The bonds were issued by the State of Montana Board of Investments to finance a portion of the costs of constructing and equipping certain sewage and solid waste disposal facilities at both the Stillwater Mine and the East Boulder Mine. The bonds mature on July 1, 2020, and have a stated interest rate of 8.00% with interest paid semi-annually. Net discounted proceeds from the offering were $28.7 million, yielding an effective interest rate of 8.57%. The balance outstanding for the years ending December 31, 2013, and 2012 was $29.6 million, which is net of unamortized discount of $0.4 million. The outstanding balance for the year ended December 31, 2011 was $29.5 million net of unamortized discount of $0.5 million. The Company made cash payments of $2.4 million for interest on the revenue bonds for the years ended December 31, 2013, 2012 and 2011.
	ASSET-BACKED REVOLVING CREDIT FACILITY
	In December 2011, the Company signed a $100.0 million asset-backed revolving credit agreement, incurring debt issuance costs of $1.1 million. In January 2012, the Company completed the syndication of this facility and simultaneously expanded the maximum line of credit to $125.0 million, incurring additional debt issuance costs of $0.2 million. Borrowings under this working capital facility are limited to a borrowing base comprised of 85% of eligible accounts receivable and 70% of eligible inventories. Terms of the agreement state that the borrowings will be secured by the Company’s accounts receivable, metals inventories and other accounts. The asset-backed revolving credit facility includes a single fixed-charge coverage covenant that only takes effect when less than 30% of the total borrowing capacity under the line remains available. The facility also includes a $60.0 million letter of credit sub-facility. Outstanding borrowings under the facility accrue interest at a spread over the London Interbank Offer Rate that varies from 2.25% to 2.75%, decreasing progressively as the percentage drawn against the facility increases. The Company also pays an unused line fee on the committed but unutilized balance under the facility at a rate per annum of 0.375% or 0.5%, depending on utilization of the facility. The asset-backed revolving credit agreement contains a “change in control” provision which if triggered would constitute an event of default under the credit agreement. On July 1, 2013, following the Company's 2013 election of directors that resulted in a change of control event, the Company was issued a waiver by the four banks that have provide commitments under the facility.
	The Company recognized approximately $1.1 million and $1.0 million in fees associated with the asset-backed revolving credit facility for the years ended December 31, 2013, and 2012, respectively. Amortization expense related to the issuance costs of the credit agreement for the years ended December 31, 2013, and 2012 was approximately $0.3 million. As of December 31, 2013, there was no drawn balance under this revolving credit facility, and approximately $17.5 million in undrawn irrevocable letters of credit have been issued under this facility as collateral for sureties.
	CAPITAL LEASE OBLIGATIONS
	The Company is party to a lease agreement with General Electric Capital Corporation (GECC) covering the acquisition of a tunnel-boring machine for use on the Blitz development adjacent to the Stillwater Mine. The transaction is structured as a capital lease with a four-year term maturing in 2016; lease payments are due quarterly in advance. The Company made cash payments of $2.2 million on its capital lease obligations for the year ended December 31, 2013. These cash payments included interest of $0.3 million. As of December 31, 2013, the outstanding principal balance under the capital lease was $4.6 million.
	The following is a schedule by year of the future minimum lease payments for the capital lease together with the present value of the net minimum lease payments:
	Year ended December 31, 2013 (In thousands)
	2014	$	2,168
	2015	2,168
	2016	590
	Total minimum lease payments	$	4,926
	Less interest at rates ranging from 5.21% to 5.46% (before-tax)	322
	Net minimum lease payments	$	4,604
	Less current portion	1,958
	Total long-term capital lease obligation	$	2,646
	CAPITALIZED INTEREST
	The Company capitalizes interest incurred on its various debt instruments as a cost of specific and identified projects under development. For the periods ended December 31, 2013, and 2012, the Company capitalized interest of $4.8 million and $0.9 million, respectively. Capitalized interest is recorded as a reduction to Interest expense in the Company's Consolidated Statements of Comprehensive (Loss) Income.

Mineral_Properties_and_Mine_De

Mineral Properties and Mine Development	12 Months Ended
	Dec. 31, 2013
Mineral Properties [Abstract]	'
Mineral Properties and Mine Development	'
	MINERAL PROPERTIES AND MINE DEVELOPMENT
	Mineral properties and mine development at December 31, 2013, and 2012, consisted of the following:
	(In thousands)	2013			2012
	Mineral Properties:
	Montana, United States of America
	Stillwater Mine	1,950			—
	Ontario, Canada
	Marathon properties	$	50,915		$	184,278
	Coldwell Complex property	4,417			14,056
	San Juan, Argentina
	Altar property	101,970			392,387
	Mine Development:
	Montana, United States of America
	Stillwater Mine	532,480			464,882
	East Boulder Mine	179,263			155,878
	Ontario, Canada
	Marathon	—			13,721
		870,995			1,225,202
	Less accumulated depletion and amortization	(365,397		)	(325,977		)
	Total mineral properties and mine development	$	505,598		$	899,225
	The Company acquired the assets of Peregrine Metals Ltd., a Canadian exploration company, in October 2011 for $166.4 million in cash (net of cash acquired) and approximately 12.03 million Stillwater common shares with a fair value of $96.5 million on the date of acquisition. During the year ended December 31, 2012, the Company recorded adjustments to the purchase price of its foreign mineral interests to reflect final tax bases and rates applicable to the properties. An impairment charge of $290.4 million (before-tax) was taken on the Altar mineral property in the third quarter of 2013, reflecting an estimated fair market value of $102.0 million. An impairment charge of $170.5 million (before-tax) was taken on the Marathon mineral properties and related mine development in the fourth quarter of 2013, reflecting an estimated fair market value of $55.3 million. See "Note 4 - Asset Impairment" for further information.

Property_Plant_and_Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Property, Plant and Equipment	'
	PROPERTY, PLANT AND EQUIPMENT
	Property, plant and equipment at December 31, consisted of the following:
	(In thousands)	2013			2012
	Machinery and equipment	$	138,351		$	107,957
	Buildings and structural components	160,076			145,347
	Land	8,592			8,418
	Construction-in-progress:
	Stillwater Mine	5,818			18,515
	East Boulder Mine	1,057			888
	Marathon	402			238
	Processing facilities and other	5,841			11,247
		$	320,137		$	292,610
	Less accumulated depreciation	(195,406		)	(169,933		)
	Total property, plant, and equipment	$	124,731		$	122,677
	An impairment charge of $0.8 million (before-tax) was taken on the Marathon property, plant and equipment in the fourth quarter of 2013 reflecting an estimated fair market value of $1.9 million. See "Note 4 - Asset Impairment" for further information.
	The Company’s capital outlay for the years ended December 31, was as follows:
	(In thousands)	2013			2012			2011
	Stillwater Mine	$	83,548		$	86,541		$	69,168
	East Boulder Mine	24,979			10,443			18,888
	Marathon project	12,380			8,319			13,470
	Altar project	101			18			63
	Other	8,021			7,427			351
	Total capital outlay	$	129,029		$	112,748		$	101,940
	Acquired by capital lease transactions	—			(677		)	—
	Total cash paid	$	129,029		$	112,071		$	101,940

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 summary sets forth the annual changes to the Company’s asset retirement obligation in 2013, 2012 and 2011:
	(In thousands)	Stillwater		East		Total
		Mine		Boulder
				Mine
	Balance at December 31, 2010	$	6,253	$	494	$	6,747
	Accretion expense	541		43		584
	Balance at December 31, 2011	$	6,794	$	537	$	7,331
	Accretion expense	587		47		634
	Balance at December 31, 2012	$	7,381	$	584	$	7,965
	Accretion expense	639		50		689
	Balance at December 31, 2013	$	8,020	$	634	$	8,654
	No adjustments were made to the asset retirement obligations in 2013, 2012 and 2011. The Company estimates the mine life of the Stillwater Mine and the East Boulder Mine to the year 2032 and 2080, respectively.
	At December 31, 2013, the Company had posted surety bonds with the State of Montana in the amount of $33.3 million to satisfy the current financial guarantee requirements determined by the regulatory agencies. The final updated environmental impact statement (EIS) was completed during the second quarter of 2012 and the Company is expecting the review process to extend through the first quarter of 2014 and anticipates these financial guarantee requirements may increase.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	FAIR VALUE MEASUREMENTS
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants. A three-level fair value hierarchy prioritizes the inputs used to measure fair value. This hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The classification of each financial asset or liability within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels of inputs used to measure fair value are as follows:
	•	Level 1 – Quoted prices in active markets for identical assets or liabilities.
	•	Level 2 – Observable inputs other than quoted prices included in Level 1, such as 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 inputs that are observable or can be corroborated by observable market data.
	•	Level 3 – Unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities.
	Financial assets and liabilities measured at fair value on a recurring basis at December 31, 2013, and 2012 consisted of the following:
	(In thousands)		Fair Value Measurements
	At December 31, 2013		Total		Level 1		Level 2		Level 3
	Mutual funds		$	604	$	604	$	—	$	—
	Investments
	Federal agency notes		$	97,585	$	—	$	97,585	$	—
	Commercial paper		$	111,753	$	—	$	111,753	$	—
	(In thousands)		Fair Value Measurements
	At December 31, 2012		Total		Level 1		Level 2		Level 3
	Mutual funds		$	1,817	$	1,817	$	—	$	—
	Investments
	Federal agency notes		$	124,715	$	—	$	124,715	$	—
	Commercial paper		$	137,268	$	—	$	137,268	$	—
	The fair value of the mutual funds is based on market prices which are readily available. The fair value of the investments is valued indirectly using observable data, quoted prices for similar assets or liabilities in active markets. Unrealized gains or losses on mutual funds and investments are recorded in Accumulated other comprehensive income (loss) on the Company's Consolidated Balance Sheets.
	Assets and liabilities measured at fair value on a nonrecurring basis at December 31, 2013, and 2012 consisted of the following:
	(In thousands)		Fair Value Measurements
	At December 31, 2013		Total		Level 1		Level 2		Level 3
	Marathon mineral properties and property, plant and equipment		$	57,272	$	—	$	—	$	57,272
	1.875 % Convertible debentures		$	2,245	$	—	$	2,245	$	—
	1.75% Convertible debentures		$	308,574	$	—	$	308,574	$	—
	Exempt facility industrial revenue bonds		$	30,050	$	—	$	—	$	30,050
	Long-term investments		$	1,021	$	1,021	$	—	$	—
	(In thousands)		Fair Value Measurements
	At December 31, 2012		Total		Level 1		Level 2		Level 3
	1.875% Convertible debentures		$	166,292	$	—	$	166,292	$	—
	1.75% Convertible debentures		$	302,466	$	—	$	302,466	$	—
	Exempt facility industrial revenue bonds		$	29,968	$	—	$	—	$	29,968
	Long-term investments		$	2,922	$	2,922	$	—	$	—
	The carrying value of the Company’s Marathon mineral properties in northern Ontario, Canada at December 31, 2013, was $228.6 million. An impairment charge of $171.4 million (before-tax) was taken on the Marathon mineral properties and property, plant and equipment in the fourth quarter of 2013 reflecting an estimated fair market value of $57.2 million. The impairment charge was included in earnings for the period.
	The Company used implicit interest rates of comparable unsecured obligations to calculate the fair value of the Company’s $30.0 million, 8% Series 2000 exempt facility industrial revenue bonds at December 31, 2013 and 2012. The Company used its current trading data to determine the fair value of each of its convertible debentures, the outstanding 1.875% convertible debentures and the outstanding 1.75% convertible debentures at December 31, 2013 and 2012.
	The fair value of the Company's long-term investments in certain Canadian junior exploration companies at December 31, 2013, and 2012 is based on market prices which are readily available. The fair market value of the Marathon mineral properties as of December 31, 2013, is based on comparable transactions for similar development stage mineral properties and market multiples for similar projects. The fair market value of the Company's Altar mineral property was remeasured at the end of the third quarter of 2013 based on Level 3 inputs such as comparable transactions for similar undeveloped mineral properties and market multiples for similar projects.

Related_Parties

Related Parties	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related Parties	'
	RELATED PARTIES
	Mitsubishi Corporation owns a 25% interest in the Company's previously wholly-owned subsidiary, Stillwater Canada Inc (SCI), which owns the Marathon PGM-copper project and related properties located in northern Ontario, Canada. The Company made PGM sales of $296.6 million and $206.4 million to Mitsubishi Corporation in 2013 and 2012, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	The Company manages risk through insurance coverage, credit monitoring and diversification of suppliers and customers. The Company also seeks to maintain adequate liquidity to offset the risk of pricing cycles.
	REFINING AGREEMENTS
	The Company has contracted with two entities to refine its filter cake production. Even though there are a limited number of PGM refiners, the Company believes that it is not economically dependent upon any one refiner.
	OPERATING LEASES
	The Company has operating leases for various mining equipment, office equipment and office space expiring at various dates through August 30, 2017. Total rental expense for cancelable and non-cancelable operating leases was $2.3 million, $2.4 million and $1.5 million in 2013, 2012 and 2011, respectively. Future minimum lease payments for operating leases with terms in excess of one year are as follows:
	Year ended (In thousands)		Minimum
			Lease
			Payment
	2014		$	474
	2015		217
	2016		146
	2017		130
	Total		$	967
	SIGNIFICANT CUSTOMERS
	Total sales to significant customers as a percentage of total revenues for the years ended December 31, were as follows:
		2013(1)			2012(1)		2011(1)
	Customer A	29	%		26	%	28	%
	Customer B	14	%		17	%	—
	Customer C	14	%		—		19	%
	Customer D	12	%		18	%	17	%
	Customer E	—			10	%	—
		69	%		71	%	64	%
	(1) The “—” symbol represents less than 10% of total revenues
	LABOR UNION CONTRACTS
	As of December 31, 2013, the Company had approximately 60% and 19% of its active labor force covered by collective bargaining agreements expiring on June 1, 2015 and December 31, 2015, respectively.
	LEGAL PROCEEDINGS
	The Company is involved in various claims and legal actions arising in the ordinary course of business, primarily employee lawsuits. In the opinion of management, the ultimate disposition of these matters is not expected to have a material adverse effect on the Company’s consolidated financial position, results of operations or liquidity.

Quarterly_Data_Unaudited

Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly Data (Unaudited)	'
	QUARTERLY DATA (UNAUDITED)
	Quarterly earnings data for the years ended December 31, 2013, and 2012 were as follows:
	(In thousands, except per share data)	2013 Quarter Ended
		March 31		June 30			September 30			December 31
	Revenue	$	250,648	$	266,491		$	280,007		$	242,360
	Depletion, depreciation and amortization	$	15,283	$	14,003		$	15,342		$	14,689
	Operating income	$	19,224	$	(4,292	)	$	(258,456	)	$	(153,099	)
	Net income (loss)	$	14,304	$	(5,657	)	$	(201,984	)	$	(108,736	)
	Comprehensive income (loss) attributable to common stockholders	$	14,657	$	(5,313	)	$	(201,276	)	$	(78,169	)
	Basic earnings (loss) per share attributable to common stockholders*	$	0.12	$	(0.04	)	$	(1.69	)	$	(0.65	)
	Diluted earnings (loss) per share attributable to common stockholders *	$	0.12	$	(0.04	)	$	(1.69	)	$	(0.65	)
	* The amounts in the table above do not equal the year-to-date amounts due to the impact of rounding.
	(In thousands, except per share data)	2012 Quarter Ended
		March 31		June 30			September 30			December 31
	Revenue	$	203,051	$	212,775		$	181,044		$	203,374
	Depletion, depreciation and amortization	$	14,672	$	14,862		$	14,107		$	14,374
	Operating income	$	1,767	$	13,627		$	9,645		$	18,597
	Net income	$	5,940	$	18,797		$	12,803		$	16,876
	Comprehensive income attributable to common stockholders	$	6,248	$	19,046		$	13,497		$	17,116
	Basic earnings per share attributable to common stockholders	$	0.05	$	0.17		$	0.11		$	0.14
	Diluted earnings per share attributable to common stockholders	$	0.05	$	0.17		$	0.11		$	0.13

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Principles of Consolidation	'
	PRINCIPLES OF CONSOLIDATION
	The accompanying consolidated financial statements include the accounts of Stillwater Mining Company, its wholly-owned subsidiaries and entities in which it holds a controlling interest (collectively referred to as the “Company”). All intercompany transactions and balances have been eliminated upon consolidation.
Cash and Cash Equivalents	'
	CASH AND CASH EQUIVALENTS
	Cash and cash equivalents consist of all cash balances and all highly liquid investments purchased with an original maturity of three months or less.
Restricted Cash	'
	RESTRICTED CASH
	Restricted cash consists of cash equivalents that have been posted as collateral in support of the Company's reclamation liabilities on outstanding letters of credit or other obligations. In the case of collateral for outstanding letters of credit, the restrictions on the balances lapse upon expiration of the letters of credit, which have terms of one year or less. Restricted cash is recorded in Other noncurrent assets on the Company's Consolidated Balance Sheets as the Company anticipates renewing the letters of credit (associated with reclamation obligations) upon expiration. Restricted cash covering other obligations is in the form of Certificates of Deposit which the Company also plans to renew upon expiration.
Investments	'
	INVESTMENTS
	Investment securities at December 31, 2013, and 2012, consist of mutual funds, federal agency notes and commercial paper with stated maturities less than three years. All securities are deemed by management to be available-for-sale and are reported at fair value. Unrealized holding gains and losses on available-for-sale securities are excluded from earnings and are reported as a separate component of other comprehensive income (loss) until realized. Realized gains and losses are based on the carrying value (cost, net of discounts or premiums) of the sold investment and recorded as a component of other income. A decline in the market value of any available-for-sale security below cost that is deemed to be other-than-temporary results in a reduction of the carrying amount of the security to fair value. The impairment is charged to earnings and a new cost basis for the security is established.
	The Company’s long-term investments in several junior exploration companies were originally recorded at cost due to less than 20% equity ownership interest and no significant Company control over the investees. A decline in the market value of these long-term investments that is deemed to be other-than-temporary will result in a reduction of the carrying amount of the investment to fair value. The impairment is charged to earnings and a new cost basis for the investment is established.
Inventories	'
	INVENTORIES
	Mined inventories are carried at the lower of current realizable value or average cost taking into consideration the Company’s long-term sales agreements and average unit costs. Production costs include the cost of direct labor and materials, depletion, depreciation and amortization, and overhead costs relating to mining and processing activities. The value of recycled inventories is determined based on the acquisition cost of the recycled material and includes all inventoriable processing costs, including direct labor, direct materials, depreciation and third-party refining costs which relate to the processing activities. Materials and supplies inventories are valued at the lower of average cost or fair market value.
Receivables	'
	RECEIVABLES
	Trade receivables and other receivable balances recorded in other current assets are reported at outstanding principal amounts, net of any required allowance for doubtful accounts. Management evaluates the collectability of receivable account balances to determine the allowance, if any. Management considers the other party’s credit risk and financial condition, as well as current and projected economic and market conditions, in determining the amount of the allowance. Receivable balances are written off when management determines that the balance is uncollectable. The Company has written down $0.6 million of the receivable balance at December 31, 2013, due to the uncertainty of ultimate payment. The Company determined that no allowance against its receivable balance at December 31, 2013 and 2012 was necessary.
Mineral Properties and Mine Development	'
	MINERAL PROPERTIES AND MINE DEVELOPMENT
	Costs of acquiring mineral properties and mineral rights are capitalized as incurred. Prior to acquiring such mineral properties or mineral rights, the Company makes a preliminary evaluation to determine that the mineral property has significant potential to develop an economic ore body. The time between initial acquisition and full evaluation of a mineral property’s potential is variable and is determined by many factors including its location relative to existing infrastructure, the mineral property’s stage of development, geological controls and relevant metal prices. When it has been determined that proven and probable ore reserves have been established in compliance with the Securities and Exchange Commission's Industry Guide 7, and a determination has been made to proceed toward commercial development, mining development costs incurred to develop the mineral property are capitalized. Mining exploration costs are expensed as incurred. If a mineable ore body is discovered, such costs are amortized when production begins using the units-of-production method based on the quantities of recoverable metal. If no mineable ore body is discovered, such costs are expensed in the period in which it is determined the mineral property has no future economic value. Costs incurred to maintain assets on a standby basis are charged to operations. Costs of abandoned projects are charged to operations upon abandonment.
	Capitalized mine development costs are expenditures incurred to increase existing production, develop new ore bodies or develop mineral property substantially in advance of production. Capitalized mine development costs include a vertical shaft, multiple surface adits and underground infrastructure development including footwall laterals, ramps, rail and transportation, electrical and ventilation systems, shop facilities, material handling areas, ore handling facilities, dewatering and pumping facilities. These expenditures are capitalized and amortized over the life of the mine or over a shorter mining period, depending on the period benefited by those expenditures, using the units-of-production method. The Company utilizes Industry Guide 7 compliant total proven and probable ore reserves, measured in tons, as the basis for determining the life of mine and uses the ore reserves in the immediate and relevant vicinity as the basis for determining the shorter mining period.
	The Company calculates amortization of capitalized mine development costs in any vicinity by applying an amortization rate to the relevant current production. The amortization rates are each based upon a ratio of unamortized capitalized mine development costs to the related ore reserves. Capital development expenditures are added to the unamortized capitalized mine development costs and amortization rates updated as the related assets are placed into service. In the calculation of the amortization rate, changes in ore reserves are accounted for as a prospective change in estimate. Ore reserves and the further benefit of capitalized mine development costs are determined based on management assumptions. Any significant changes in these assumptions, such as a change in the mine plan or a change in estimated proven and probable ore reserves could have a material effect on the expected period of benefit resulting in a potentially significant change in the amortization rate and / or the valuations of related assets. The Company’s proven ore reserves are generally expected to be extracted utilizing its existing mine development infrastructure. Additional capital expenditures will be required to access the Company’s estimated probable ore reserves. These anticipated capital expenditures are not included in the current calculation of depletion, depreciation and amortization.
	Expenditures incurred to sustain existing production and directly access specific ore reserve blocks or stopes provide benefit to ore reserve production over limited periods of time (secondary development) and are charged to operations as incurred. These costs include ramp and stope access excavations from the primary haulage levels (footwall laterals), stope material re-handling / laydown excavations, stope ore and waste pass excavations and chute installations, stope ventilation raise excavations and stope utility and pipe raise excavations.
Property, Plant and Equipment	'
	PROPERTY, PLANT AND EQUIPMENT
	Plant facilities and equipment are recorded at cost and depreciated using the straight-line method over estimated useful lives ranging from one to fifteen years or, for capital leases, the term of the related leases, if shorter. Maintenance and repairs are charged to cost of revenues as incurred.
	Interest is capitalized on expenditures related to major construction or development projects and is amortized using the same method as the related asset. Interest capitalization is discontinued when the asset is placed into operation or when development and construction cease.
Leases	'
	LEASES
	The Company classifies a lease as either capital or operating. All capital leases are depreciated over the shorter of the useful life of the asset or the lease term.
Asset Impairment	'
	ASSET IMPAIRMENT
	The Company reviews and evaluates its long-lived assets, including mineral properties and mine development, for impairment when events or changes in circumstances indicate that the related carrying amounts of its assets may not be recoverable. Impairment is considered to exist if the total estimated future cash flows on an undiscounted basis are less than the carrying amount of the asset. Future cash flows include estimates of recoverable ounces, PGM prices (historical prices or third-party projections of future prices, long-term sales contracts prices, price trends and related factors), production levels and capital and reclamation expenditures, all based on life-of-mine plans and projections. If the assets are impaired, a calculation of fair market value is performed, and if the fair market value is lower than the carrying value of the assets, the assets are reduced to their fair market value.
	Assumptions underlying future cash flows are subject to risks and uncertainties. Any differences between significant assumptions and market conditions such as PGM prices, lower than expected recoverable ounces, and / or the Company’s operating performance could have a material effect on the Company’s determination of ore reserves, or its ability to recover the carrying amounts of its long-lived assets resulting in potential additional impairment charges.
Fair Value of Financial Instruments	'
	FAIR VALUE OF FINANCIAL INSTRUMENTS
	The Company’s non-derivative financial instruments consist primarily of cash equivalents, trade receivables, payables, investments, revenue bond debt, convertible debentures and capital lease obligations. The carrying amounts of cash equivalents, trade receivables and payables approximate fair value due to their short maturities. The carrying amounts of investments approximate fair value based on market quotes.
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants. A fair value hierarchy was established which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The fair value hierarchy distinguishes among three levels of inputs that may be utilized when measuring fair value: Level 1 inputs (using quoted prices in active markets for identical assets or liabilities), Level 2 inputs (using external inputs other than Level 1 prices such as quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability) and Level 3 inputs (unobservable inputs supported by little or no market activity and based on internal assumptions used to measure assets and liabilities). The classification of each financial asset or liability within the above hierarchy is determined based on the lowest level input that is significant to the fair value measurement.
Revenue Recognition	'
	REVENUE RECOGNITION
	Revenue is comprised of Mine Production revenue, PGM Recycling revenue and other sales revenue. Mine Production revenue consists of the sales of palladium and platinum extracted by the Company’s mining operations, including any realized hedging gains or losses, and is reduced by sales discounts associated with long-term sales agreements. Mine Production revenue also consists of the sales of by-products (rhodium, gold, silver, copper and nickel) extracted by mining operations. PGM Recycling revenue consists of the sales of recycled palladium, platinum and rhodium derived from spent catalytic materials, including any unrealized and realized hedging gains or losses. PGM recycling revenue also includes revenue from toll processing. Other sales revenue consists of sales of PGMs that were acquired on the open market for resale.
	Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred either physically or through an irrevocable transfer of metals to customers’ accounts, the price is fixed or determinable, no related obligations remain and collectability is probable. Under the terms of sales contracts and purchase orders received from customers, the Company recognizes revenue when the product is in a refined and saleable form and title passes, which is typically when the product is transferred from the account of the Company to the account of the customer. Under certain of its sales agreements, the Company instructs a third-party refiner to transfer metal from the Company’s account to the customer’s account; at this point, the Company’s account at the third-party refinery is reduced and the purchaser’s account is increased by the number of ounces of metal sold. These transfers are irrevocable and the Company has no further responsibility for the delivery of the metals. Under other sales agreements, physical conveyance occurs by the Company arranging for shipment of metal from the third-party refinery to the purchaser. In these cases, revenue is recognized at the point when title passes contractually to the purchaser. Sales discounts are recognized when the related revenue is recorded. The Company classifies any sales discounts as a reduction in revenue.
Noncontrolling Interest	'
	NONCONTROLLING INTEREST
	Noncontrolling interest relates to the sale of a 25% ownership interest in Stillwater Canada Inc during 2012. Noncontrolling interest is classified in the Company's Consolidated Statements of Comprehensive (Loss) Income as part of consolidated net income (loss) and the accumulated amount of noncontrolling interest in the Company's Consolidated Balance Sheets as a component of equity.
Hedging Program	'
	HEDGING PROGRAM
	From time to time, the Company enters into derivative financial instruments, including fixed forwards, cashless put and call option collars and financially settled forwards to manage the effect of changes in the prices of palladium and platinum on the Company’s revenue and to manage interest rate risk. Derivatives are reported on the balance sheet at fair value and, if the derivative is not designated as a hedging instrument, changes in fair value must be recognized in earnings in the period of change. If the derivative is designated as a hedge, and to the extent such hedge is determined to be highly effective, changes in fair value are either (a) offset by the change in fair value of the hedged asset or liability (if applicable) or (b) reported as a component of other comprehensive income (loss) in the period of change, and subsequently recognized in the determination of net income (loss) in the period the offsetting hedged transaction occurs. If an instrument is settled early, any gains or losses are deferred and recognized as adjustments to the revenue recorded for the related hedged production when the transaction related to the original hedge instrument settles.
	Unrealized derivative gains and losses recorded in current and non-current assets and liabilities and amounts recorded in other comprehensive income (loss) and in current period earnings are non-cash items and therefore are taken into account in the preparation of the Company's Consolidated Statements of Cash Flows based on their respective balance sheet classifications.
Reclamation and Environmental Costs	'
	RECLAMATION AND ENVIRONMENTAL COSTS
	The fair value of a liability for an asset retirement obligation is recognized in the period in which it is incurred if a reasonable estimate of fair value can be made. The fair value of the liability is added to the carrying amount of the associated asset and this additional carrying amount is depreciated over the life of the asset. The liability is accreted at the end of each period through charges to operating expense. If the obligation is settled for other than the carrying amount of the liability, the Company will recognize a gain or loss on settlement.
	Accounting for reclamation obligations requires management to make estimates for each mining operation of the future costs the Company will incur to complete final reclamation work required to comply with existing laws and regulations. Actual costs incurred in future periods could differ from amounts estimated. Additionally, future changes to environmental laws and regulations could increase the extent of reclamation and remediation work that the Company is required to perform. Any such increases in future costs could materially impact the amounts charged in future periods to operations for reclamation and remediation.
Income Taxes	'
	INCOME TAXES
	The Company determines income taxes using the asset and liability method which results in the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of those assets and liabilities, as well as operating loss and tax credit carryforwards, using enacted tax rates in effect in the years in which the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets and liabilities are recorded on a jurisdictional basis.
	In assessing the realizability of U.S. and foreign deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Each quarter, management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. A valuation allowance has been provided at December 31, 2013, and 2012, for the portion of the Company’s net deferred tax assets for which it is more likely than not that they will not be realized.
Stock-based Compensation	'
	STOCK-BASED COMPENSATION
	Costs resulting from all share-based payment transactions are recognized in the financial statements over the respective vesting periods and determined using a fair-value-based measurement method. The fair values for stock options and other stock-based compensation awards issued to employees are estimated at the date of grant using a Black-Scholes option pricing model.
Earnings (Loss) Per Common Share	'
	EARNINGS (LOSS) PER COMMON SHARE
	Basic earnings (loss) per share attributable to common stockholders is computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted earnings (loss) per share attributable to common stockholders reflects the potential dilution that could occur if the Company’s dilutive outstanding stock options or nonvested shares were exercised and the Company’s convertible debentures were converted. Reported net income (loss) attributable to common stockholders is adjusted for the interest expense net of capitalized interest (including amortization expense of deferred debt and equity fees), the related income tax effect and the income (loss) attributable to the noncontrolling interest in the computation of basic and diluted earnings per share attributable to common stockholders. The Company currently has only one class of equity shares outstanding.
Comprehensive Income (Loss)	'
	COMPREHENSIVE INCOME (LOSS)
	Comprehensive income (loss) includes net income (loss), as well as other changes in stockholders’ equity that result from transactions and events other than those with stockholders. The Company’s only significant elements of other comprehensive income in 2013, 2012 and 2011 consisted of unrealized gains and losses related to available-for-sale marketable securities.
Debt Issuance Costs	'
	DEBT ISSUANCE COSTS
	Debt issuance costs are capitalized and amortized to interest expense using the effective interest method over the lives of the related debt agreements.
Advertising Costs	'
	ADVERTISING COSTS
	Advertising (marketing) costs are expensed as incurred.
Use of Estimates	'
	USE OF ESTIMATES
	The preparation of the Company’s consolidated financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. The more significant areas requiring the use of management’s estimates relate to mineral reserves, reclamation and environmental obligations, valuation allowance for deferred tax assets, useful lives utilized for depletion, depreciation, amortization and accretion calculations, future cash flows from long-lived assets, fair value of long-lived assets, and fair value of derivatives. Actual results could differ from these estimates.
	During the fourth quarter of 2013, the Company updated its estimates for useful lives of its machinery and equipment; buildings and structural components assets in order to better match the Company's depreciation expense with the periods these assets are expected to generate revenue based on planned and historical operations. The new estimated useful lives were established based on historical replacement data and internal usage data. The Company accounted for this useful life update as a changes in accounting estimate as of December 1, 2013, in accordance with the guidance of ASC Topic 250, Accounting Changes and Error Correction, thereby impacting the quarter in which the change occurred and future quarters. The effect of this change on depreciation was a decrease of $0.5 million for the fourth quarter and year ended December 31, 2013.
Foreign Currency Transactions	'
	FOREIGN CURRENCY TRANSACTIONS
	The functional currency of the Company’s Canadian and South American subsidiaries is the U.S. dollar. Gains or losses resulting from transactions denominated in Canadian and South American currencies are included in Foreign currency transaction gain, net in the Company's Consolidated Statements of Comprehensive (Loss) Income.
Reclassification	'
	RECLASSIFICATION
	Prior year amount previously disclosed as restricted cash has been consolidated into other noncurrent assets to conform to the current year presentation on the Company's consolidated balance sheets. Prior year total amount previously disclosed as mineral properties and mine development, net has been separated into two separate components: mineral properties, and mine development, net to conform to the current year presentation on the Company's consolidated balance sheets. Prior year amount previously disclosed as other has been separated into changes in other assets and changes in other liabilities to conform to current year presentation on the Company's consolidated statements of cash flows.

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Company's Outstanding Commodity Derivatives	'
	The following is a summary of the Company’s commodity derivatives as of December 31, 2013:
	PGM Recycling:	Platinum			Palladium			Rhodium
	Fixed Forward Contracts
	Settlement Period	Ounces	Average Price		Ounces	Average Price		Ounces	Average Price
	First Quarter 2014	26,997	$	1,409	46,043	$	728	7,277	$	951
	Second Quarter 2014	1,761	$	1,356	1,696	$	721	988	$	899

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Nonvested Share Activity	'
	Nonvested share activity during 2013, 2012 and 2011, is detailed in the following table:
	Year ended December 31,	Nonvested		Weighted-
		Shares		Average
				Grant-
				Date Fair
				Value
	Nonvested shares at December 31, 2010	1,563,886		$	7.51
	Granted	369,417		22.49
	Vested	(429,425	)	15.1
	Forfeited	(1,267	)	18.78
	Nonvested shares at December 31, 2011	1,502,611		$	10.95
	Granted	653,712		13.12
	Vested	(927,228	)	7.98
	Forfeited	(79,762	)	13.8
	Nonvested shares at December 31, 2012	1,149,333		$	14.38
	Granted	544,122		13.64
	Vested (1)	(1,661,783	)	14.19
	Forfeited	(615	)	13.99
	Nonvested shares at December 31, 2013	31,057		$	11.55
	(1) Pursuant to the terms of the Company's Equity Plans, the change in control that occurred in the second quarter of 2013 resulted in all outstanding nonvested shares granted under those Equity Plans immediately becoming fully vested.
Option Pricing Valuation Assumptions	'
	The fair value for options granted in 2011 was estimated at the date of grant using a Black-Scholes option pricing model with the following weighted-average assumptions:
	Year ended December 31,	2011
	Weighted average expected lives (years)	3.5
	Interest rate	0.8	%
	Volatility	67	%
	Dividend yield	—
Stock Option Activity	'
	Stock option activity for the years ended December 31, 2013, 2012 and 2011, is summarized as follows (excluding the effect of nonvested shares):
	Year Ended December 31,	Shares		Weighted				Weighted-
				Average				Average
				Exercise				Grant-
				Price				Date Fair
								Value
	Options outstanding at December 31, 2010	595,939		$	20.54
	Options exercisable at December 31, 2010	530,724		21.32
	2011 Activity
	Options granted	103,479		6.87				$	5.14
	Options exercised	(52,131	)	15.1
	Options canceled/forfeited	(155,175	)	33.25
	Options outstanding at December 31, 2011	492,112		$	14.23
	Options exercisable at December 31, 2011	454,966		14.06
	2012 Activity
	Options granted	—		—
	Options exercised	(16,552	)	2.61
	Options canceled/forfeited	(233,041	)	18.86
	Options outstanding at December 31, 2012	242,519		$	10.57
	Options exercisable at December 31, 2012	224,933		10.08
	2013 Activity
	Options granted	—		—
	Options exercised	(25,471	)	5.02
	Options canceled/forfeited	(17,757	)	6.07
	Options outstanding at December 31, 2013	199,291		$	11.68
	Options exercisable at December 31, 2013	199,291		11.68
Information for Outstanding and Exercisable Options	'
	The following table summarizes information for outstanding and exercisable options as of December 31, 2013:
				Options Outstanding						Options Exercisable
	Range of Exercise	Number		Weighted Average		Weighted				Number	Weighted
	Price	Outstanding		Remaining		Average				Exercisable	Average
				Contract		Exercise					Exercise
				Life		Price					Price
	$  3.96 - $  4.66	1,292		4.8		$	4.3			1,292	$	4.3
	$  4.67 - $  9.33	80,039		2.1		$	6.92			80,039	$	6.92
	$  9.34 - $13.99	42,159		3.8		$	12.04			42,159	$	12.04
	$14.00 - $18.65	53,151		1.8		$	15.1			53,151	$	15.1
	$18.66 - $23.31	21,050		6.5		$	19.95			21,050	$	19.95
	$23.32 - $24.55	1,600		7.1		$	24.41			1,600	$	24.41
		199,291		2.9		$	11.68			199,291	$	11.68
Summary of Status of and Changes in Nonvested Stock Options	'
	A summary of the status of the Company’s nonvested stock options as of December 31, 2013, and changes during the year then ended, is presented below:
	Nonvested Options	Options		Weighted-
				Average
				Grant-
				Date Fair
				Value
	Nonvested options at January 1, 2013	17,586		$	8.19
	Options vested (1)	(17,586	)	8.19
	Nonvested options at December 31, 2013	—
	(1) Pursuant to the terms of the Company's Equity Plans, the change in control that occurred in the second quarter of 2013 resulted in all outstanding nonvested shares granted under those Equity Plans immediately becoming fully vested.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Schedule of Deferred Tax Assets and Liabilities	'
	The components of the Company’s deferred income tax liabilities (assets) are comprised of the following temporary differences and carryforwards at December 31, 2013, and 2012.
	December 31, (In thousands)	2013			2012
	Mine development and mineral interests-US	$	105,366		$	112,867
	Mine development and mineral interests-Canada	(1,234		)	49,758
	Mineral interests-South America	27,333			111,961
	Long-term debt	49,936			56,281
	Total deferred tax liabilities	$	181,401		$	330,867
	Noncurrent liabilities	(9,928		)	(12,644		)
	Property and equipment	(18,502		)	(14,214		)
	Current liabilities	(20,696		)	(20,243		)
	Long-term investments	(3,108		)	(2,372		)
	Inventory	(1,972		)	(1,061		)
	AMT credit and other carryforwards	(17,021		)	(5,989		)
	Exploration	(5,391		)	(4,815		)
	Net operating loss and other carryforwards	(67,856		)	(109,556		)
	Total deferred tax assets	$	(144,474	)	$	(170,894	)
	Valuation allowance	20,685			18,525
	Net deferred tax assets	(123,789		)	(152,369		)
	Net deferred tax liabilities	$	57,612		$	178,498
Reconciliation of the Federal Income Tax Provision	'
	Reconciliation of the income tax provision at the applicable statutory income tax rates to the effective rate is as follows:
	Year ended December 31, (In thousands)	2013			2012			2011
	(Loss) income before income taxes	$	(395,726	)	$	50,377		$	155,530
	Income tax (benefit) provision at statutory rates	(138,504		)	18,302			53,648
	State income tax expense, net of federal benefit	3,995			4,173			6,898
	Percentage depletion	(8,786		)	(4,985		)	(37,163		)
	Foreign currency transaction gain, net	31,605			(5,304		)	(1,131		)
	NOL utilization adjustment	—			(4,277		)	—
	Compensation related adjustment	359			2,026			1,700
	Change in valuation allowance	5,595			(14,514		)	(13,937		)
	Return-to-provision	1,097			—			—
	Foreign rate differential	8,895			—			—
	Other	2,091			540			1,220
	Net income tax (benefit) provision	$	(93,653	)	$	(4,039	)	$	11,235
Schedule of Components of Income Tax (Benefit) Provision	'
	The income tax (benefit) provision is comprised of the following:
	Year ended December 31, (In thousands)	2013			2012			2011
	Current
	Federal	$	9,740		$	1,721		$	11,235
	State	5,152			200			—
	Current income tax	$	14,892		$	1,921		$	11,235
	Deferred
	Federal	5,278			—			—
	State	252			—			—
	Foreign	(114,075		)	(5,960		)	—
	Deferred income tax benefit	(108,545		)	(5,960		)	—
	Income tax (benefit) provision	$	(93,653	)	$	(4,039	)	$	11,235
Schedule of Earnings (Losses) Before Income Taxes	'
	The components of (loss) income before income tax benefit (provision) by tax jurisdiction for the years ended December 31, 2013, 2012 and 2011 were as follows:
	(In millions)	2013			2012			2011
	United States	$	61,671		$	60,166		$	157,215
	Foreign	(457,397		)	(9,789		)	(1,685		)
	(Loss) income before income tax benefit (provision)	$	(395,726	)	$	50,377		$	155,530

Comprehensive_GainLoss_Tables

Comprehensive Gain/(Loss) (Tables)	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Changes in Accumulated Other Comprehensive Loss	'
	The following summary sets forth the changes in Accumulated other comprehensive income (loss) during 2013, 2012 and 2011:
	(In thousands)	Available-for-Sale
		Securities
	Balance at December 31, 2010	$	(852	)
	Change in value	(109		)
	Comprehensive loss	$	(109	)
	Balance at December 31, 2011	$	(961	)
	Change in value	862
	Comprehensive gain	$	862
	Balance at December 31, 2012	$	(99	)
	Change in value	105
	Comprehensive gain	$	105
	Balance at December 31, 2013	$	6

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Financial Information Related To The Company's Business Segments	'
	The following financial information relates to the Company’s business segments:
	(In thousands)	Mine		PGM		Canadian			South			All			Total
		Production		Recycling		Properties			American			Other
	Year ended December 31, 2013								Properties
	Revenues	$	478,918	$	560,588	$	—		$	—		$	—		$	1,039,506
	Depletion, depreciation and amortization	$	58,201	$	1,116	$	—		$	—		$	—		$	59,317
	General and administrative expenses	$	—	$	—	$	1,112		$	2,549		$	38,324		$	41,985
	Interest income	$	—	$	3,375	$	20		$	184		$	902		$	4,481
	Interest expense	$	—	$	—	$	—		$	—		$	22,957		$	22,957
	Income (loss) before impairment charge and income taxes	$	106,122	$	35,463	$	(4,255	)	$	8,845		$	(80,146	)	$	66,029
	Impairment charge	$	—	$	—	$	171,338		$	290,417		$	—		$	461,755
	Income (loss) after impairment charge, before income taxes	$	106,122	$	35,463	$	(175,593	)	$	(281,572	)	$	(80,146	)	$	(395,726	)
	Capital expenditures	$	108,527	$	330	$	12,380		$	101		$	7,691		$	129,029
	Total assets	$	553,153	$	80,555	$	83,800		$	109,960		$	519,212		$	1,346,680
	(In thousands)	Mine		PGM		Canadian			South			All			Total
		Production		Recycling		Properties			American			Other
	Year ended December 31, 2012								Properties
	Revenues	$	455,426	$	344,818	$	—		$	—		$	—		$	800,244
	Depletion, depreciation and amortization	$	56,960	$	1,055	$	—		$	—		$	—		$	58,015
	General and administrative expenses	$	—	$	—	$	3,785		$	3,334		$	33,829		$	40,948
	Interest income	$	—	$	2,293	$	29		$	208		$	(205	)	$	2,325
	Interest expense	$	—	$	—	$	12		$	—		$	10,908		$	10,920
	Income (loss) before income taxes	$	109,255	$	10,452	$	(7,344	)	$	(2,254	)	$	(59,732	)	$	50,377
	Capital expenditures	$	96,307	$	353	$	8,319		$	18		$	7,074		$	112,071
	Total assets	$	470,251	$	92,899	$	258,918		$	412,836		$	655,859		$	1,890,763
	(In thousands)	Mine		PGM		Canadian			South			All			Total
		Production		Recycling		Properties			American			Other
	Year ended December 31, 2011								Properties
	Revenues	$	528,007	$	376,820	$	—		$	—		$	1,142		$	905,969
	Depletion, depreciation and amortization	$	61,312	$	1,066	$	—		$	—		$	—		$	62,378
	General and administrative expenses	$	—	$	—	$	2,511		$	2,163		$	37,398		$	42,072
	Interest income	$	—	$	2,228	$	—		$	66		$	1,280		$	3,574
	Interest expense	$	—	$	—	$	—		$	—		$	6,548		$	6,548
	Income (loss) before income taxes	$	197,250	$	18,816	$	(2,576	)	$	(2,097	)	$	(55,863	)	$	155,530
	Capital expenditures	$	88,056	$	243	$	13,470		$	63		$	108		$	101,940
	Total assets	$	416,740	$	70,901	$	196,706		$	440,942		$	202,035		$	1,327,324

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Investments [Abstract]	'
Available-for-sale Securities by Major Security Type and Class	'
	The amortized cost, gross unrealized gains, gross unrealized losses, and fair market value of available-for-sale investment securities by major security type and class of security at December 31, are as follows:
	(In thousands)	Amortized		Gross		Gross			Fair
		Cost		unrealized		unrealized			market
				gains		losses			value
	2013
	Federal agency notes	$	97,509	$	76	$	—		$	97,585
	Commercial paper	112,063		10		(320		)	111,753
	Mutual funds	359		245		—			604
	Total	$	209,931	$	331	$	(320	)	$	209,942
	2012
	Federal agency notes	$	124,682	$	37	$	(4	)	$	124,715
	Commercial paper	137,661		3		(396		)	137,268
	Mutual funds	1,556		261		—			1,817
	Total	$	263,899	$	301	$	(400	)	$	263,800
Maturities of Available-for-sale Securities	'
	The maturities of available-for-sale securities at December 31, 2013, are as follows:
	(In thousands)	Amortized cost		Fair market value
	Federal agency notes
	Due in one year or less	$	48,359	$	48,401
	Due after one year through three years	49,150		49,184
	Total	$	97,509	$	97,585
	Commercial paper
	Due in one year or less	$	92,142	$	91,871
	Due after one year through three years	19,921		19,882
	Total	$	112,063	$	111,753

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2013
Inventory Disclosure [Abstract]	'
Components Of Inventories	'
	Inventories reflected in the accompanying balance sheets at December 31, consisted of the following:
	(In thousands)	2013		2012
	Metals inventory
	Raw ore	$	4,638	$	3,505
	Concentrate and in-process	67,251		51,498
	Finished goods	60,100		74,942
		$	131,989	$	129,945
	Materials and supplies	26,661		23,263
	Total inventory	$	158,650	$	153,208

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Reconciliation of Basic and Diluted Earnings Per Share	'
	Reconciliations showing the computation of basic and diluted shares and the related impact on income for the years ended December 31, 2012 and 2011 are shown in the following table:
		Year Ended					Year Ended
		31-Dec-12					31-Dec-11
	(In thousands, except per share amounts)	Income (Numerator)		Weighted Average Shares (Denominator)	Per Share Amount		Income		Weighted	Per
							(Numerator)		Average	Share
									Shares	Amount
									(Denominator)
	Basic EPS
	Net income attributable to common stockholders	$	55,045	116,162	$	0.47	$	144,295	105,846	$	1.36
	Effect of Dilutive Securities
	Stock options	—		58			—		60
	Nonvested shares	—		762			—		958
	1.875% Convertible debentures, net of tax	2,355		7,082			3,651		7,082
	1.75% Convertible debentures, net of tax	2,774		7,377			—		—
	Diluted EPS
	Net income attributable to common stockholders and assumed conversions	$	60,174	131,441	$	0.46	$	147,946	113,946	$	1.3

Debt_and_Capital_Lease_Obligat1

Debt and Capital Lease Obligations (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Schedule of Future Minimum Lease Payments for Capital Leases	'
	The following is a schedule by year of the future minimum lease payments for the capital lease together with the present value of the net minimum lease payments:
	Year ended December 31, 2013 (In thousands)
	2014	$	2,168
	2015	2,168
	2016	590
	Total minimum lease payments	$	4,926
	Less interest at rates ranging from 5.21% to 5.46% (before-tax)	322
	Net minimum lease payments	$	4,604
	Less current portion	1,958
	Total long-term capital lease obligation	$	2,646

Mineral_Properties_and_Mine_De1

Mineral Properties and Mine Development (Tables)	12 Months Ended
	Dec. 31, 2013
Mineral Properties [Abstract]	'
Schedule Of Components Of Mineral Properties	'
	Mineral properties and mine development at December 31, 2013, and 2012, consisted of the following:
	(In thousands)	2013			2012
	Mineral Properties:
	Montana, United States of America
	Stillwater Mine	1,950			—
	Ontario, Canada
	Marathon properties	$	50,915		$	184,278
	Coldwell Complex property	4,417			14,056
	San Juan, Argentina
	Altar property	101,970			392,387
	Mine Development:
	Montana, United States of America
	Stillwater Mine	532,480			464,882
	East Boulder Mine	179,263			155,878
	Ontario, Canada
	Marathon	—			13,721
		870,995			1,225,202
	Less accumulated depletion and amortization	(365,397		)	(325,977		)
	Total mineral properties and mine development	$	505,598		$	899,225

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Schedule of Property, Plant and Equipment	'
	Property, plant and equipment at December 31, consisted of the following:
	(In thousands)	2013			2012
	Machinery and equipment	$	138,351		$	107,957
	Buildings and structural components	160,076			145,347
	Land	8,592			8,418
	Construction-in-progress:
	Stillwater Mine	5,818			18,515
	East Boulder Mine	1,057			888
	Marathon	402			238
	Processing facilities and other	5,841			11,247
		$	320,137		$	292,610
	Less accumulated depreciation	(195,406		)	(169,933		)
	Total property, plant, and equipment	$	124,731		$	122,677
Schedule of Capital Expenditures	'
	The Company’s capital outlay for the years ended December 31, was as follows:
	(In thousands)	2013			2012			2011
	Stillwater Mine	$	83,548		$	86,541		$	69,168
	East Boulder Mine	24,979			10,443			18,888
	Marathon project	12,380			8,319			13,470
	Altar project	101			18			63
	Other	8,021			7,427			351
	Total capital outlay	$	129,029		$	112,748		$	101,940
	Acquired by capital lease transactions	—			(677		)	—
	Total cash paid	$	129,029		$	112,071		$	101,940

Asset_Retirement_Obligation_Ta

Asset Retirement Obligation (Tables)	12 Months Ended
	Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Changes in Asset Retirement Obligation	'
	The following summary sets forth the annual changes to the Company’s asset retirement obligation in 2013, 2012 and 2011:
	(In thousands)	Stillwater		East		Total
		Mine		Boulder
				Mine
	Balance at December 31, 2010	$	6,253	$	494	$	6,747
	Accretion expense	541		43		584
	Balance at December 31, 2011	$	6,794	$	537	$	7,331
	Accretion expense	587		47		634
	Balance at December 31, 2012	$	7,381	$	584	$	7,965
	Accretion expense	639		50		689
	Balance at December 31, 2013	$	8,020	$	634	$	8,654

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Financial Assets And Liabilities Measured At Fair Value On A Recurring Basis	'
	Financial assets and liabilities measured at fair value on a recurring basis at December 31, 2013, and 2012 consisted of the following:
	(In thousands)	Fair Value Measurements
	At December 31, 2013	Total		Level 1		Level 2		Level 3
	Mutual funds	$	604	$	604	$	—	$	—
	Investments
	Federal agency notes	$	97,585	$	—	$	97,585	$	—
	Commercial paper	$	111,753	$	—	$	111,753	$	—
	(In thousands)	Fair Value Measurements
	At December 31, 2012	Total		Level 1		Level 2		Level 3
	Mutual funds	$	1,817	$	1,817	$	—	$	—
	Investments
	Federal agency notes	$	124,715	$	—	$	124,715	$	—
	Commercial paper	$	137,268	$	—	$	137,268	$	—
Financial Assets And Liabilities Measured At Fair Value On A Nonrecurring Basis	'
	Assets and liabilities measured at fair value on a nonrecurring basis at December 31, 2013, and 2012 consisted of the following:
	(In thousands)	Fair Value Measurements
	At December 31, 2013	Total		Level 1		Level 2		Level 3
	Marathon mineral properties and property, plant and equipment	$	57,272	$	—	$	—	$	57,272
	1.875 % Convertible debentures	$	2,245	$	—	$	2,245	$	—
	1.75% Convertible debentures	$	308,574	$	—	$	308,574	$	—
	Exempt facility industrial revenue bonds	$	30,050	$	—	$	—	$	30,050
	Long-term investments	$	1,021	$	1,021	$	—	$	—
	(In thousands)	Fair Value Measurements
	At December 31, 2012	Total		Level 1		Level 2		Level 3
	1.875% Convertible debentures	$	166,292	$	—	$	166,292	$	—
	1.75% Convertible debentures	$	302,466	$	—	$	302,466	$	—
	Exempt facility industrial revenue bonds	$	29,968	$	—	$	—	$	29,968
	Long-term investments	$	2,922	$	2,922	$	—	$	—

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	'
	Future minimum lease payments for operating leases with terms in excess of one year are as follows:
	Year ended (In thousands)		Minimum
			Lease
			Payment
	2014		$	474
	2015		217
	2016		146
	2017		130
	Total		$	967
Schedule Of Total Sales To Significant Customers As A Percentage Of Total Revenues	'
	Total sales to significant customers as a percentage of total revenues for the years ended December 31, were as follows:
		2013(1)			2012(1)		2011(1)
	Customer A	29	%		26	%	28	%
	Customer B	14	%		17	%	—
	Customer C	14	%		—		19	%
	Customer D	12	%		18	%	17	%
	Customer E	—			10	%	—
		69	%		71	%	64	%
	(1) The “—” symbol represents less than 10% of total revenues

Quarterly_Data_Unaudited_Table

Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Schedule of Quarterly Financial Information	'
	Quarterly earnings data for the years ended December 31, 2013, and 2012 were as follows:
	(In thousands, except per share data)	2013 Quarter Ended
		March 31		June 30			September 30			December 31
	Revenue	$	250,648	$	266,491		$	280,007		$	242,360
	Depletion, depreciation and amortization	$	15,283	$	14,003		$	15,342		$	14,689
	Operating income	$	19,224	$	(4,292	)	$	(258,456	)	$	(153,099	)
	Net income (loss)	$	14,304	$	(5,657	)	$	(201,984	)	$	(108,736	)
	Comprehensive income (loss) attributable to common stockholders	$	14,657	$	(5,313	)	$	(201,276	)	$	(78,169	)
	Basic earnings (loss) per share attributable to common stockholders*	$	0.12	$	(0.04	)	$	(1.69	)	$	(0.65	)
	Diluted earnings (loss) per share attributable to common stockholders *	$	0.12	$	(0.04	)	$	(1.69	)	$	(0.65	)
	* The amounts in the table above do not equal the year-to-date amounts due to the impact of rounding.
	(In thousands, except per share data)	2012 Quarter Ended
		March 31		June 30			September 30			December 31
	Revenue	$	203,051	$	212,775		$	181,044		$	203,374
	Depletion, depreciation and amortization	$	14,672	$	14,862		$	14,107		$	14,374
	Operating income	$	1,767	$	13,627		$	9,645		$	18,597
	Net income	$	5,940	$	18,797		$	12,803		$	16,876
	Comprehensive income attributable to common stockholders	$	6,248	$	19,046		$	13,497		$	17,116
	Basic earnings per share attributable to common stockholders	$	0.05	$	0.17		$	0.11		$	0.14
	Diluted earnings per share attributable to common stockholders	$	0.05	$	0.17		$	0.11		$	0.13

Nature_of_Operations_Details

Nature of Operations (Details)	12 Months Ended
	Dec. 31, 2013
	mi
	Project
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Number of expansion projects	3
Location of development of underground mining area, number of miles west of mineshaft	3

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2013	Mar. 31, 2012
					Minimum [Member]	Maximum [Member]	Stillwater Canada, Inc. [Member]
Property, Plant and Equipment [Line Items]	'	'	'	'	'	'	'
Letters of credit, expiration terms	'	'	'	'	'	'1 year	'
Available-for-sale, stated maturities, less than	'	'3 years	'3 years	'	'	'	'
Equity method investment, ownership percentage	20.00%	20.00%	'	'	'	'	'
Loss on trade receivables	'	$632,000	$0	$0	'	'	'
Property, plant, and equipment, useful life	'	'	'	'	'1 year	'15 years	'
Noncontrolling interest purchased by third party	'	'	'	'	'	'	25.00%
Advertising costs	'	4,400,000	10,800,000	11,300,000	'	'	'
Effect of change in accounting estimate, decrease in after-tax earnings	$500,000	'	'	'	'	'	'

Sales_Narrative_Details

Sales (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Sales [Line Items]	'	'	'
Platinum group metals purity percentage	99.95%	'	'
Rhodium purity percentage	99.90%	'	'
Revenues from by-product sales	$27,100,000	$30,600,000	$36,000,000
Term of supply agreement	'1 year	'	'
PGMs purchased in the open market and re-sold	0	0	1,142,000
PGM Recycling [Member]	'	'	'
Sales [Line Items]	'	'	'
Write down of recycling advances	'	$600,000	$600,000

Asset_Impairment_Details

Asset Impairment (Details) (USD $)	12 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2013
				Marathon Properties [Member]	San Juan, Argentina [Member]	Mining Properties and Mineral Rights [Member]	Construction in Progress [Member]
					Altar Property [Member]	Marathon Properties [Member]	Marathon Properties [Member]
Impaired Long-Lived Assets Held and Used [Line Items]	'	'	'	'	'	'	'
Impairment charge	$461,755,000	$0	$0	$171,400,000	$290,400,000	$170,500,000	$800,000
Marathon mineral properties and property, plant and equipment	'	'	'	'	102,000,000	'	'
Mineral properties and mine development, and property, plant and equipment, net	'	'	'	228,600,000	'	'	'
Mineral properties and mine development, and property, plant and equipment, estimated fair market value	'	'	'	$57,200,000	'	'	'

Noncontrolling_Interest_Detail

Noncontrolling Interest (Details) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Mar. 31, 2012	Dec. 31, 2013	Mar. 31, 2012
			Noncontrolling Interest [Member]	Additional paid in capital [Member]	Noncontrolling Interest [Member]	Stillwater Canada, Inc. [Member]
Noncontrolling Interest [Line Items]	'	'	'	'	'	'
Noncontrolling interest purchased by third party	'	'	'	'	'	25.00%
Cash paid for 25% interest in SCI by Mitsubishi Corp	'	'	'	'	'	$81,250,000
Amount contributed to SCI for initial cash call by Mitsubishi Corp	'	'	'	'	'	13,600,000
Maximum PGM production purchase percentage	100.00%	'	'	'	'	'
Issuance of noncontrolling interest	'	'	'	42,500,000	'	'
Expenses incurred for issuance of noncontrolling interest	'	'	'	1,100,000	'	'
Noncontrolling interest	19,894,000	51,761,000	19,894,000	'	'	'
Asset Impairment Charges	'	'	'	'	$42,300,000	'

Derivative_Instruments_Company

Derivative Instruments (Company's Outstanding Commodity Derivatives) (Details)	12 Months Ended
	Dec. 31, 2013
	oz
First Quarter 2014 [Member] | Platinum [Member]	'
Derivative [Line Items]	'
Ounces	26,997
Average Price	1,409
First Quarter 2014 [Member] | Palladium [Member]	'
Derivative [Line Items]	'
Ounces	46,043
Average Price	728
First Quarter 2014 [Member] | Rhodium [Member]	'
Derivative [Line Items]	'
Ounces	7,277
Average Price	951
Second Quarter 2014 [Member] | Platinum [Member]	'
Derivative [Line Items]	'
Ounces	1,761
Average Price	1,356
Second Quarter 2014 [Member] | Palladium [Member]	'
Derivative [Line Items]	'
Ounces	1,696
Average Price	721
Second Quarter 2014 [Member] | Rhodium [Member]	'
Derivative [Line Items]	'
Ounces	988
Average Price	899

ShareBased_Compensation_Change

Share-Based Compensation (Changes In The Company's Nonvested Shares) (Details) (Nonvested Shares [Member], USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Nonvested Shares [Member]	'		'	'
Nonvested Shares	'		'	'
Nonvested, Beginning Balance	1,149,333		1,502,611	1,563,886
Nonvested Shares, Granted	544,122		653,712	369,417
Nonvested Shares, Vested	-1,661,783	[1]	-927,228	-429,425
Nonvested Shares, Forfeited	-615		-79,762	-1,267
Nonvested, Ending Balance	31,057		1,149,333	1,502,611
Weighted-Average Grant-Date Fair Value	'		'	'
Nonvested shares, Weighted-Average Grant-Date Fair Value, Beginning of Period (in usd per share)	$14.38		$10.95	$7.51
Nonvested shares, Weighted-Average Grant-Date Fair Value, Granted (in usd per share)	$13.64		$13.12	$22.49
Nonvested shares, Weighted-Average Grant-Date Fair Value, Vested (in usd per share)	$14.19	[1]	$7.98	$15.10
Nonvested shares, Weighted-Average Grant-Date Fair Value, Forfeited (in usd per share)	$13.99		$13.80	$18.78
Nonvested shares, Weighted-Average Grant-Date Fair Value, End of Period (in usd per share)	$11.55		$14.38	$10.95
[1]	Pursuant to the terms of the Company's Equity Plans, the change in control that occurred in the second quarter of 2013 resulted in all outstanding nonvested shares granted under those Equity Plans immediately becoming fully vested.

ShareBased_Compensation_Weight

Share-Based Compensation (Weighted Average Assumptions) (Details)	12 Months Ended
	Dec. 31, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Weighted average expected lives (years)	'3 years 6 months
Interest rate	0.80%
Volatility	67.00%
Dividend yield	0.00%

ShareBased_Compensation_Stock_

Share-Based Compensation (Stock Option Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Shares	'	'	'
Options outstanding, Shares, Beginning Balance	242,519	492,112	595,939
Options exercisable, Shares, Beginning Balance	224,933	454,966	530,724
Options granted, Shares	0	0	103,479
Options exercised, Shares	-25,471	-16,552	-52,131
Options canceled/forfeited, Shares	-17,757	-233,041	-155,175
Options outstanding, Shares, Ending Balance	199,291	242,519	492,112
Options exercisable, Shares, Ending Balance	199,291	224,933	454,966
Weighted Average Exercise Price	'	'	'
Options outstanding, Weighted Average Exercise Price, Beginning of Period	$10.57	$14.23	$20.54
Options exercisable, Weighted Average Exercise Price, Beginning of Period	$10.08	$14.06	$21.32
Options granted, Weighted Average Exercise Price	$0	$0	$6.87
Options exercised, Weighted Average Exercise Price	$5.02	$2.61	$15.10
Options canceled/forfeited, Weighted Average Exercise Price	$6.07	$18.86	$33.25
Options outstanding, Weighted Average Exercise Price, End of Period	$11.68	$10.57	$14.23
Options exercisable, Weighted Average Exercise Price, End of Period	$11.68	$10.08	$14.06
Options granted, Weighted-Average Grant-Date Fair Value	'	'	$5.14

ShareBased_Compensation_Outsta

Share-Based Compensation (Outstanding and Exercisable Options) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Options Outstanding, Shares, Number	199,291	242,519	492,112	595,939
Options Outstanding, Average Remaining Contract Life (years)	'2 years 11 months 1 day	'	'	'
Options Outstanding, Weighted Average Exercise Price	$11.68	$10.57	$14.23	$20.54
Options Exercisable, Shares, Number	199,291	224,933	454,966	530,724
Options Exercisable, Weighted Average Exercise Price	$11.68	$10.08	$14.06	$21.32
Range of Exercise Price $ 3.96 - $ 4.66 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower range limit	$3.96	'	'	'
Exercise Price Range, Upper Range Limit	$4.66	'	'	'
Options Outstanding, Shares, Number	1,292	'	'	'
Options Outstanding, Average Remaining Contract Life (years)	'4 years 9 months 17 days	'	'	'
Options Outstanding, Weighted Average Exercise Price	$4.30	'	'	'
Options Exercisable, Shares, Number	1,292	'	'	'
Options Exercisable, Weighted Average Exercise Price	$4.30	'	'	'
Range of Exercise Price $ 4.67 - $ 9.33 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower range limit	$4.67	'	'	'
Exercise Price Range, Upper Range Limit	$9.33	'	'	'
Options Outstanding, Shares, Number	80,039	'	'	'
Options Outstanding, Average Remaining Contract Life (years)	'2 years 1 month 17 days	'	'	'
Options Outstanding, Weighted Average Exercise Price	$6.92	'	'	'
Options Exercisable, Shares, Number	80,039	'	'	'
Options Exercisable, Weighted Average Exercise Price	$6.92	'	'	'
Range of Exercise Price $ 9.34 - $13.99 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower range limit	$9.34	'	'	'
Exercise Price Range, Upper Range Limit	$13.99	'	'	'
Options Outstanding, Shares, Number	42,159	'	'	'
Options Outstanding, Average Remaining Contract Life (years)	'3 years 9 months 23 days	'	'	'
Options Outstanding, Weighted Average Exercise Price	$12.04	'	'	'
Options Exercisable, Shares, Number	42,159	'	'	'
Options Exercisable, Weighted Average Exercise Price	$12.04	'	'	'
Range of Exercise Price $14.00 - $18.65 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower range limit	$14	'	'	'
Exercise Price Range, Upper Range Limit	$18.65	'	'	'
Options Outstanding, Shares, Number	53,151	'	'	'
Options Outstanding, Average Remaining Contract Life (years)	'1 year 9 months 20 days	'	'	'
Options Outstanding, Weighted Average Exercise Price	$15.10	'	'	'
Options Exercisable, Shares, Number	53,151	'	'	'
Options Exercisable, Weighted Average Exercise Price	$15.10	'	'	'
Range of Exercise Price $18.66 - $23.31 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower range limit	$18.66	'	'	'
Exercise Price Range, Upper Range Limit	$23.31	'	'	'
Options Outstanding, Shares, Number	21,050	'	'	'
Options Outstanding, Average Remaining Contract Life (years)	'6 years 6 months 4 days	'	'	'
Options Outstanding, Weighted Average Exercise Price	$19.95	'	'	'
Options Exercisable, Shares, Number	21,050	'	'	'
Options Exercisable, Weighted Average Exercise Price	$19.95	'	'	'
Range of Exercise Price $23.32 - $24.55 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower range limit	$23.32	'	'	'
Exercise Price Range, Upper Range Limit	$24.55	'	'	'
Options Outstanding, Shares, Number	1,600	'	'	'
Options Outstanding, Average Remaining Contract Life (years)	'7 years 1 month 15 days	'	'	'
Options Outstanding, Weighted Average Exercise Price	$24.41	'	'	'
Options Exercisable, Shares, Number	1,600	'	'	'
Options Exercisable, Weighted Average Exercise Price	$24.41	'	'	'

ShareBased_Compensation_Nonves

Share-Based Compensation (Nonvested Stock Options) (Details) (Nonvested Stock Options [Member], USD $)	12 Months Ended
	Dec. 31, 2013
Nonvested Stock Options [Member]	'
Options	'
Nonvested options, Shares, beginning balance	17,586
Options vested, Shares	-17,586	[1]
Nonvested options, Shares, ending balance	0
Weighted- Average Grant- Date Fair Value	'
Nonvested options, Weighted-Average Grant-Date Fair Value, beginning of period (in usd per share)	$8.19
Options vested, Weighted-Average Grant-Date Fair Value	$8.19	[1]
Nonvested options, Weighted-Average Grant-Date Fair Value, end of period (in usd per share)	'
[1]	Pursuant to the terms of the Company's Equity Plans, the change in control that occurred in the second quarter of 2013 resulted in all outstanding nonvested shares granted under those Equity Plans immediately becoming fully vested.

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative) (Details) (USD $)

12 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

7-May-13

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Plan

Director

Maximum [Member]

Maximum [Member]

Maximum [Member]

Peregrine Metals Ltd. [Member]

Employees Options [Member]

Officers And Directors Options [Member]

Nonvested Shares [Member]

Nonvested Shares [Member]

Nonvested Shares [Member]

Nonvested Shares [Member]

Nonvested Shares [Member]

Stock Options [Member]

Stock Options [Member]

2004 and 2012 Plans Combined [Member]

2012 Equity Incentive Plan [Member]

2004 Equity Incentive Plan [Member]

General Employee Plan [Member]

1994 Incentive Plan [Member]

Non Employee Directors Deferral Plan [Member]

Non Employee Directors Deferral Plan [Member]

Non Employee Directors Deferral Plan [Member]

Nonqualified Deferred Compensation Plan [Member]

Nonqualified Deferred Compensation Plan [Member]

Nonqualified Deferred Compensation Plan [Member]

Nonqualified Deferred Compensation Plan [Member]

Employee Benefit Plans [Member]

Employee Benefit Plans [Member]

Employee Benefit Plans [Member]

General and Administrative Expense [Member]

General and Administrative Expense [Member]

General and Administrative Expense [Member]

Accelerate Share-based Compensation Expense [Member]

General and Administrative Expense [Member]

General and Administrative Expense [Member]

Maximum [Member]

Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares of common stock authorized for issuance under the plan

16,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

5,200,000

1,400,000

4,800,000

'

'

'

'

'

'

'

'

'

'

Number of terminated plans

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares available and reserved for grant

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Award vesting period

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Award expiration period

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of new directors elected

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of directors retained

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensation expense related to the accelerated vesting of unvested stock options and nonvested shares

$9,063,000

$0

$0

'

'

'

'

'

'

'

'

'

'

'

$9,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation expense

'

'

'

'

'

'

'

'

'

'

13,700,000

4,600,000

8,200,000

6,400,000

'

41,400

96,870

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash from exercise of stock options

128,000

44,000

787,000

'

100,000

100,000

800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensation expense related to nonvested shares expected to be recognized in 2014

'

'

'

'

'

'

'

'

'

'

119,100

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensation expense related to nonvested shares expected to be recognized in 2015

'

'

'

'

'

'

'

'

'

'

119,400

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensation expense related to nonvested shares expected to be recognized in 2016

'

'

'

'

'

'

'

'

'

'

106,400

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employer matching contribution percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20.00%

'

'

'

'

'

'

'

'

'

Share-based compensation expense deferred in common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

64,200

83,400

69,150

'

'

'

'

'

'

'

Deferred compensation arrangement, percentage of salaries deferred

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

60.00%

'

'

'

Deferred compensation arrangement, percentage of cash compensation other than salaries deferred

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

'

'

'

100.00%

'

'

Deferred compensation arrangement, percentage of restricted stock units upon vesting allowed to defer

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

'

'

'

'

'

'

Deferred compensation arrangement, percentage of total compensation deferred

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.00%

8.00%

'

'

Share-based compensation expense deferred in cash

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

203,000

342,000

248,800

'

'

'

'

Total intrinsic value of stock options exercised

200,000

200,000

400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total intrinsic value of options outstanding

500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Replacement options issued upon closing of business acquisition

'

'

'

'

'

'

'

96,154

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of savings plans

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

Percentage of eligible compensation employees may elect to contribute to savings plan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

60.00%

'

'

Number of shares issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

900,000

700,000

400,000

Shares issued in period, market value on grant date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10,300,000

$7,900,000

$5,600,000

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2003
Operating Loss Carryforwards [Line Items]	'	'	'	'
Net operating loss and other carryforwards	$67,856,000	$109,556,000	'	'
Regular tax net operating loss carryforwards	195,500,000	'	'	'
Usage of net operating losses	95,000,000	'	'	100,500,000
Alternative minimum tax credit carryforwards	15,700,000	'	'	'
General business credits	1,200,000	'	'	'
State tax net operating loss carryforwards	2,900,000	'	'	'
Foreign net operating loss and other deductions	44,800,000	'	'	'
Income tax receivable	600,000	'	'	'
Accrued interest and penalties on unrecognized tax benefits	2,100,000	100,000	'	'
Interest and penalties	1,400,000	200,000	0	'
U.S. operations [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Net operating loss and other carryforwards	56,100,000	99,300,000	'	'
Foreign operations [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Net operating loss and other carryforwards	11,800,000	10,300,000	'	'
State income taxes [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Cash payments for income taxes	100,000	0	0	'
U.S. federal [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Cash payments for income taxes	5,200,000	4,800,000	'	'
Norilsk Nickel [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Usage of net operating losses	$77,700,000	'	'	$10,200,000

Income_Taxes_Components_Of_Def

Income Taxes (Components Of Deferred Tax Liabilities (Assets)) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule Of Deferred Tax Assets (Liabilities) [Line Items]	'	'
Long-term debt	$49,936	$56,281
Total deferred tax liabilities	181,401	330,867
Noncurrent liabilities	-9,928	-12,644
Property and equipment	-18,502	-14,214
Current liabilities	-20,696	-20,243
Long-term investments	-3,108	-2,372
Inventory	-1,972	-1,061
AMT credit and other carryforwards	-17,021	-5,989
Exploration	-5,391	-4,815
Net operating loss and other carryforwards	-67,856	-109,556
Total deferred tax assets	-144,474	-170,894
Valuation allowance	20,685	18,525
Net deferred tax assets	-123,789	-152,369
Net deferred tax liabilities	57,612	178,498
United States [Member]	'	'
Schedule Of Deferred Tax Assets (Liabilities) [Line Items]	'	'
Mine development costs	105,366	112,867
Canada [Member]	'	'
Schedule Of Deferred Tax Assets (Liabilities) [Line Items]	'	'
Mine development costs	-1,234	49,758
South America [Member]	'	'
Schedule Of Deferred Tax Assets (Liabilities) [Line Items]	'	'
Mine development costs	$27,333	$111,961

Income_Taxes_Reconciliation_Of

Income Taxes (Reconciliation Of The Federal Income Tax Provision) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
(Loss) income before income taxes	($395,726)	$50,377	$155,530
Income tax (benefit) provision at statutory rates	-138,504	18,302	53,648
State income tax expense, net of federal benefit	3,995	4,173	6,898
Percentage depletion	-8,786	-4,985	-37,163
Foreign currency transaction gain, net	31,605	-5,304	-1,131
NOL utilization adjustment	0	-4,277	0
Compensation related adjustment	359	2,026	1,700
Change in valuation allowance	5,595	-14,514	-13,937
Effective Income Tax Rate Reconciliation, Return to Provision True Ups	1,097	0	0
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	8,895	0	0
Other	2,091	540	1,220
Income tax (benefit) provision	($93,653)	($4,039)	$11,235

Income_Taxes_Components_of_Inc

Income Taxes (Components of Income Tax (Benefit) Provision) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current	'	'	'
Federal	$9,740	$1,721	$11,235
State	5,152	200	0
Current income tax	14,892	1,921	11,235
Deferred	'	'	'
Federal	5,278	0	0
State	252	0	0
Foreign	-114,075	-5,960	0
Deferred income tax benefit	-108,545	-5,960	0
Income tax (benefit) provision	($93,653)	($4,039)	$11,235

Income_Taxes_Schedule_of_Earni

Income Taxes (Schedule of Earnings (Losses) Before Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income (Loss) From Continuing Operations Before Income Taxes, Minority Interest, And Income (Loss) From Equity Method Investments [Line Items]	'	'	'
(Loss) income before income tax benefit (provision)	($395,726)	$50,377	$155,530
United States	'	'	'
Income (Loss) From Continuing Operations Before Income Taxes, Minority Interest, And Income (Loss) From Equity Method Investments [Line Items]	'	'	'
(Loss) income before income tax benefit (provision)	61,671	60,166	157,215
Foreign	'	'	'
Income (Loss) From Continuing Operations Before Income Taxes, Minority Interest, And Income (Loss) From Equity Method Investments [Line Items]	'	'	'
(Loss) income before income tax benefit (provision)	($457,397)	($9,789)	($1,685)

Comprehensive_GainLoss_Changes

Comprehensive Gain/(Loss) (Changes In Accumulated Other Comprehensive Loss) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in Accumulated Other Comprehensive (Loss) [Roll Forward]	'	'	'
Balance at end of period	$6	($99)	'
Available-for-sale Securities [Member]	'	'	'
Changes in Accumulated Other Comprehensive (Loss) [Roll Forward]	'	'	'
Balance at beginning of period	-99	-961	-852
Change in value	105	862	-109
Comprehensive loss	105	862	-109
Balance at end of period	$6	($99)	($961)

Segment_Information_Narrative_

Segment Information (Narrative) (Details) (USD $)	12 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Sep. 30, 2013
	Segment			Mine Production [Member]	San Juan, Argentina [Member]
				Business_Component	Altar Property [Member]
Segment Reporting Information [Line Items]	'	'	'	'	'
Number of business segments	5	'	'	'	'
Number of business components	'	'	'	2	'
Impairment of Long-Lived Assets Held-for-use	$461,755	$0	$0	$0	$290,400

Segment_Information_Financial_

Segment Information (Financial Information Related To The Company's Business Segments) (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 Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	$242,360	$280,007	$266,491	$250,648	$203,374	$181,044	$212,775	$203,051	$1,039,506	$800,244	$905,969
Depletion, depreciation and amortization	'	'	'	'	'	'	'	'	59,317	58,015	62,378
General and administrative expenses	'	'	'	'	'	'	'	'	41,985	40,948	42,072
Interest income	'	'	'	'	'	'	'	'	4,481	2,325	3,574
Interest expense	'	'	'	'	'	'	'	'	22,957	10,920	6,548
Income (loss) before impairment charge and income taxes	'	'	'	'	'	'	'	'	66,029	'	'
Impairment charge	'	'	'	'	'	'	'	'	461,755	0	0
(LOSS) INCOME BEFORE INCOME TAX BENEFIT (PROVISION)	'	'	'	'	'	'	'	'	-395,726	50,377	155,530
Capital expenditures	'	'	'	'	'	'	'	'	129,029	112,071	101,940
Total assets	1,346,680	'	'	'	1,890,763	'	'	'	1,346,680	1,890,763	1,327,324
Mine Production [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	478,918	455,426	528,007
Depletion, depreciation and amortization	'	'	'	'	'	'	'	'	58,201	56,960	61,312
General and administrative expenses	'	'	'	'	'	'	'	'	0	0	0
Interest income	'	'	'	'	'	'	'	'	0	0	0
Interest expense	'	'	'	'	'	'	'	'	0	0	0
Income (loss) before impairment charge and income taxes	'	'	'	'	'	'	'	'	106,122	'	'
Impairment charge	'	'	'	'	'	'	'	'	0	'	'
(LOSS) INCOME BEFORE INCOME TAX BENEFIT (PROVISION)	'	'	'	'	'	'	'	'	106,122	109,255	197,250
Capital expenditures	'	'	'	'	'	'	'	'	108,527	96,307	88,056
Total assets	553,153	'	'	'	470,251	'	'	'	553,153	470,251	416,740
PGM Recycling [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	560,588	344,818	376,820
Depletion, depreciation and amortization	'	'	'	'	'	'	'	'	1,116	1,055	1,066
General and administrative expenses	'	'	'	'	'	'	'	'	0	0	0
Interest income	'	'	'	'	'	'	'	'	3,375	2,293	2,228
Interest expense	'	'	'	'	'	'	'	'	0	0	0
Income (loss) before impairment charge and income taxes	'	'	'	'	'	'	'	'	35,463	'	'
Impairment charge	'	'	'	'	'	'	'	'	0	'	'
(LOSS) INCOME BEFORE INCOME TAX BENEFIT (PROVISION)	'	'	'	'	'	'	'	'	35,463	10,452	18,816
Capital expenditures	'	'	'	'	'	'	'	'	330	353	243
Total assets	80,555	'	'	'	92,899	'	'	'	80,555	92,899	70,901
Canadian Properties [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	0	0	0
Depletion, depreciation and amortization	'	'	'	'	'	'	'	'	0	0	0
General and administrative expenses	'	'	'	'	'	'	'	'	1,112	3,785	2,511
Interest income	'	'	'	'	'	'	'	'	20	29	0
Interest expense	'	'	'	'	'	'	'	'	0	12	0
Income (loss) before impairment charge and income taxes	'	'	'	'	'	'	'	'	-4,255	'	'
Impairment charge	'	'	'	'	'	'	'	'	171,338	'	'
(LOSS) INCOME BEFORE INCOME TAX BENEFIT (PROVISION)	'	'	'	'	'	'	'	'	-175,593	-7,344	-2,576
Capital expenditures	'	'	'	'	'	'	'	'	12,380	8,319	13,470
Total assets	83,800	'	'	'	258,918	'	'	'	83,800	258,918	196,706
South American Properties [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	0	0	0
Depletion, depreciation and amortization	'	'	'	'	'	'	'	'	0	0	0
General and administrative expenses	'	'	'	'	'	'	'	'	2,549	3,334	2,163
Interest income	'	'	'	'	'	'	'	'	184	208	66
Interest expense	'	'	'	'	'	'	'	'	0	0	0
Income (loss) before impairment charge and income taxes	'	'	'	'	'	'	'	'	8,845	'	'
Impairment charge	'	'	'	'	'	'	'	'	290,417	'	'
(LOSS) INCOME BEFORE INCOME TAX BENEFIT (PROVISION)	'	'	'	'	'	'	'	'	-281,572	-2,254	-2,097
Capital expenditures	'	'	'	'	'	'	'	'	101	18	63
Total assets	109,960	'	'	'	412,836	'	'	'	109,960	412,836	440,942
All Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	0	0	1,142
Depletion, depreciation and amortization	'	'	'	'	'	'	'	'	0	0	0
General and administrative expenses	'	'	'	'	'	'	'	'	38,324	33,829	37,398
Interest income	'	'	'	'	'	'	'	'	902	-205	1,280
Interest expense	'	'	'	'	'	'	'	'	22,957	10,908	6,548
Income (loss) before impairment charge and income taxes	'	'	'	'	'	'	'	'	-80,146	'	'
Impairment charge	'	'	'	'	'	'	'	'	0	'	'
(LOSS) INCOME BEFORE INCOME TAX BENEFIT (PROVISION)	'	'	'	'	'	'	'	'	-80,146	-59,732	-55,863
Capital expenditures	'	'	'	'	'	'	'	'	7,691	7,074	108
Total assets	$519,212	'	'	'	$655,859	'	'	'	$519,212	$655,859	$202,035

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]	'	'	'
Loss on long-term investments	($1,894,000)	($2,562,000)	$0
Other noncurrent assets [Member]	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'
Long-term Investments	$1,000,000	'	'

Investments_Availableforsale_S

Investments (Available-for-sale Securities by Major Security Type and Class) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Available-for-sale Securities [Abstract]	'	'
Amortized Cost	$209,931	$263,899
Gross unrealized gains	331	301
Gross unrealized losses	-320	-400
Fair market value	209,942	263,800
Federal agency notes [Member]	'	'
Available-for-sale Securities [Abstract]	'	'
Amortized Cost	97,509	124,682
Gross unrealized gains	76	37
Gross unrealized losses	0	-4
Fair market value	97,585	124,715
Commercial paper [Member]	'	'
Available-for-sale Securities [Abstract]	'	'
Amortized Cost	112,063	137,661
Gross unrealized gains	10	3
Gross unrealized losses	-320	-396
Fair market value	111,753	137,268
Mutual funds [Member]	'	'
Available-for-sale Securities [Abstract]	'	'
Amortized Cost	359	1,556
Gross unrealized gains	245	261
Gross unrealized losses	0	0
Fair market value	$604	$1,817

Investments_Maturities_of_Avai

Investments -(Maturities of Available-for-sale Securities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Amortized cost	'	'
Amortized Cost	$209,931	$263,899
Fair market value	'	'
Fair market value	209,942	263,800
Federal agency notes [Member]	'	'
Amortized cost	'	'
Due in one year or less	48,359	'
Due after one year through three years	49,150	'
Amortized Cost	97,509	124,682
Fair market value	'	'
Due in one year or less	48,401	'
Due after one year through three years	49,184	'
Fair market value	97,585	124,715
Commercial paper [Member]	'	'
Amortized cost	'	'
Due in one year or less	92,142	'
Due after one year through three years	19,921	'
Amortized Cost	112,063	137,661
Fair market value	'	'
Due in one year or less	91,871	'
Due after one year through three years	19,882	'
Fair market value	$111,753	$137,268

Inventories_Details

Inventories (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Metals inventory	'	'
Raw ore	$4,638	$3,505
Concentrate and in-process	67,251	51,498
Finished goods	60,100	74,942
Metals inventory	131,989	129,945
Materials and supplies	26,661	23,263
Total inventory	$158,650	$153,208

Earnings_Per_Common_Share_Narr

Earnings Per Common Share (Narrative) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
			Stock Options, Excluded due to Net Loss [Member]	Stock Options, Excluded due to Market Price Less Than Exercise Price [Member]	Stock Options, Excluded due to Market Price Less Than Exercise Price [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'	'
Antidilutive securities excluded from computation of diluted earnings per share	'	'	45,269	121,569	273,965
Nonvested shares included in computation of diluted earnings per share	762,060	957,604	'	'	'

Earnings_Per_Common_Share_Comp

Earnings Per Common Share (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $)

3 Months Ended

12 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, 2012

Dec. 31, 2011

Dec. 31, 2013

Mar. 31, 2008

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Oct. 31, 2012

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.75% convertible debentures [Member]

1.75% convertible debentures [Member]

1.75% convertible debentures [Member]

1.75% convertible debentures [Member]

Basic EPS

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income attributable to common stockholders

($108,736)

($201,984)

($5,657)

$14,304

$16,876

$12,803

$18,797

$5,940

($270,206)

$55,045

$144,295

'

'

'

'

'

'

'

'

Basic EPS, Weighted Average Shares (Denominator) (in shares)

'

'

'

'

'

'

'

'

118,607,000

116,162,000

105,846,000

'

'

'

'

'

'

'

'

Basic (loss) earnings per share attributable to common stockholders

($0.65)

[1]

($1.69)

[1]

($0.04)

[1]

$0.12

[1]

$0.14

$0.11

$0.17

$0.05

($2.28)

$0.47

$1.36

'

'

'

'

'

'

'

'

Effect of Dilutive Securities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Effect of convertible debentures, net of tax

'

'

'

'

'

'

'

'

'

'

'

2,355

3,651

'

'

2,774

0

'

'

Effect of stock options (in shares)

'

'

'

'

'

'

'

'

'

58,000

60,000

'

'

'

'

'

'

'

'

Effect of nonvested shares (in shares)

'

'

'

'

'

'

'

'

'

762,060

957,604

'

'

'

'

'

'

'

'

Effect of convertible debentures (in shares)

'

'

'

'

'

'

'

'

'

'

'

7,082,000

7,082,000

'

'

7,377,000

0

'

'

Diluted EPS

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income attributable to common stockholders and assumed conversions

'

'

'

'

'

'

'

'

'

$60,174

$147,946

'

'

'

'

'

'

'

'

Diluted (in shares)

'

'

'

'

'

'

'

'

118,607,000

131,441,000

113,946,000

'

'

'

'

'

'

'

'

Diluted (loss) earnings per share attributable to common stockholders

($0.65)

[1]

($1.69)

[1]

($0.04)

[1]

$0.12

[1]

$0.13

$0.11

$0.17

$0.05

($2.28)

$0.46

$1.30

'

'

'

'

'

'

'

'

Debt instrument, stated rate

'

'

'

'

'

'

'

'

'

'

'

'

'

1.88%

1.88%

1.75%

'

1.75%

1.75%

[1]

{F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjcwYzFiZjk0OTJmMjRkZjY4ZjIzMzFjMTY4YjYyN2JifFRleHRTZWxlY3Rpb246NjlGQzgwNjgzMUFBNkFFREUwMUQ4NjMzRjFEQzQwMDYM}

Debt_and_Capital_Lease_Obligat2

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

1 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Jun. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

7-May-13

Mar. 18, 2013

Oct. 31, 2009

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2009

Mar. 31, 2008

Oct. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2000

Jan. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Director

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.875% convertible debentures [Member]

1.75% convertible debentures [Member]

1.75% convertible debentures [Member]

1.75% convertible debentures [Member]

1.75% convertible debentures [Member]

8% Series 2000 [Member]

8% Series 2000 [Member]

8% Series 2000 [Member]

8% Series 2000 [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Letter of Credit [Member]

Minimum [Member]

Maximum [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, face amount

'

'

'

'

'

'

'

'

'

'

'

$181,500,000

$396,750,000

'

'

'

$30,000,000

'

'

$30,000,000

'

'

'

'

'

'

'

Debt instrument, stated rate

'

'

'

'

'

'

'

1.88%

'

'

'

1.88%

1.75%

1.75%

1.75%

1.75%

8.00%

'

'

'

'

'

'

'

'

'

'

Common stock issuable on conversion of debt per $1,000 (in shares)

'

'

'

'

'

'

'

42.5351

'

'

'

'

'

'

60.4961

'

'

'

'

'

'

'

'

'

'

'

'

Debt conversion price (in usd per share)

'

'

'

'

'

'

'

$23.51

'

'

'

'

'

'

$16.53

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debentures exchanged for shares, value

'

'

'

'

'

'

15,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debentures exchanged for shares, shares

'

'

'

'

'

'

1,840,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount of senior convertible debentures

'

'

'

'

'

'

'

2,200,000

'

'

166,500,000

'

'

'

274,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Repayments of convertible debt

'

'

'

'

'

164,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization expense related to issuance costs

'

1,664,000

1,495,000

988,000

'

'

'

200,000

900,000

900,000

'

'

'

'

1,100,000

200,000

'

'

'

'

'

'

300,000

300,000

'

'

'

Interest expense

'

'

'

'

'

'

'

300,000

3,100,000

3,100,000

'

'

'

'

18,300,000

4,500,000

'

'

'

'

'

'

'

'

'

'

'

Cash payments for interest

'

300,000

'

'

'

'

'

1,600,000

3,100,000

3,100,000

'

'

'

'

6,900,000

0

2,400,000

2,400,000

2,400,000

'

'

'

'

'

'

'

'

Warrant conversion ratio (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30.2481

'

'

'

'

'

'

'

'

'

'

'

'

Warrant conversion price (in usd per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$16.53

'

'

'

'

'

'

'

'

'

'

'

'

Equity component of convertible debenture

'

'

'

'

'

'

'

'

'

'

'

'

141,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt issuance costs

'

'

'

'

'

'

'

'

'

'

'

'

'

12,400,000

'

'

'

'

'

'

200,000

1,100,000

'

'

'

'

'

Debt issuance costs, amortization period (in months)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

Net proceeds from the offering

'

0

403,926,000

0

'

'

'

'

'

'

'

'

384,300,000

'

'

'

'

'

'

28,700,000

'

'

'

'

'

'

'

Debt, Weighted Average Interest Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.57%

'

'

'

'

'

'

'

'

'

'

Debt instrument, effective interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.50%

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized discount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

122,800,000

'

400,000

400,000

500,000

'

'

'

'

'

'

'

'

Long-term debt, balance outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

29,600,000

29,600,000

29,500,000

'

'

'

'

'

'

'

'

Credit agreement, maximum borrowing capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

125,000,000

100,000,000

'

'

'

'

60,000,000

Borrowing base comprised eligible accounts receivable

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

85.00%

'

'

'

'

Borrowing base comprised eligible accounts inventories

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

70.00%

'

'

'

'

Percentage of capacity available when covenant takes effect (less than 30%)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30.00%

'

Description of variable interest rate basis

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'London Interbank Offer Rate

'

'

'

'

Basis spread on variable interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.25%

2.75%

'

Unused capacity, commitment fee percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.38%

0.50%

'

Number of directors retained

'

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of new directors elected

'

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fees recognized

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,100,000

1,000,000

'

'

'

Undrawn letters of credit issued as collateral for sureties

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

17,500,000

'

'

'

'

Capital Lease Obligations [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital lease term

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital lease obligations incurred during the period

'

0

677,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital lease obligations, principal and interest payments

'

2,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest included in payments

'

300,000

'

'

'

'

'

1,600,000

3,100,000

3,100,000

'

'

'

'

6,900,000

0

2,400,000

2,400,000

2,400,000

'

'

'

'

'

'

'

'

Capital lease obligations

'

4,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalized Interest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalized interest

'

$4,800,000

$900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt_and_Capital_Lease_Obligat3

Debt and Capital Lease Obligations (Schedule of Future Minimum Lease Payments for Capital Leases) (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Capital Lease Obligations [Abstract]	'
2014	$2,168
2015	2,168
2016	590
Total minimum lease payments	4,926
Less interest at rates ranging from 5.21% to 5.46% (before-tax)	322
Net minimum lease payments	4,604
Less current portion	1,958
Total long-term capital lease obligation	$2,646
Minimum [Member]	'
Capital Lease Obligations [Abstract]	'
Capital lease, interest rate	5.21%
Maximum [Member]	'
Capital Lease Obligations [Abstract]	'
Capital lease, interest rate	5.46%

Mineral_Properties_and_Mine_De2

Mineral Properties and Mine Development (Details) (USD $)

12 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

Share data in Millions, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Oct. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2013

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, 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

Peregrine Metals Ltd. [Member]

Marathon Properties [Member]

Marathon Properties [Member]

Altar Property [Member]

Mineral Properties and Mine Development [Member]

Mineral Properties and Mine Development [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mining Properties and Mineral Rights [Member]

Mine Development [Member]

Mine Development [Member]

Mine Development [Member]

Mine Development [Member]

Mine Development [Member]

Mine Development [Member]

Ontario, Canada [Member]

San Juan, Argentina [Member]

Stillwater Mine [Member]

Stillwater Mine [Member]

Marathon Properties [Member]

Marathon Properties [Member]

Marathon Properties [Member]

Coldwell Complex Property [Member]

Coldwell Complex Property [Member]

Altar Property [Member]

Altar Property [Member]

Stillwater Mine [Member]

Stillwater Mine [Member]

Marathon Properties [Member]

Marathon Properties [Member]

East Boulder Mine [Member]

East Boulder Mine [Member]

Montana, United States of America [Member]

Montana, United States of America [Member]

Ontario, Canada [Member]

Ontario, Canada [Member]

Ontario, Canada [Member]

Ontario, Canada [Member]

San Juan, Argentina [Member]

San Juan, Argentina [Member]

Montana, United States of America [Member]

Montana, United States of America [Member]

Ontario, Canada [Member]

Ontario, Canada [Member]

Montana, United States of America [Member]

Montana, United States of America [Member]

Mineral Properties and Mine Development [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Mineral Properties and Mine Development, Gross

'

'

'

'

'

'

'

$870,995,000

$1,225,202,000

$1,950,000

$0

'

$50,915,000

$184,278,000

$4,417,000

$14,056,000

$101,970,000

$392,387,000

$532,480,000

$464,882,000

$0

$13,721,000

$179,263,000

$155,878,000

Less accumulated depletion and amortization

'

'

'

'

'

'

'

-365,397,000

-325,977,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total mineral properties and mine development

505,598,000

899,225,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisitions [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash paid for acquisition (net of cash acquired)

'

'

'

166,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of common shares issued for acquisition

'

'

'

12.03

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common shares issued for acquisition, fair value

'

'

'

96,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Asset Impairment Charges [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment charge

461,755,000

0

0

'

171,400,000

'

290,400,000

'

'

'

'

170,500,000

'

'

'

'

'

'

'

'

'

'

'

'

Marathon mineral properties and property, plant and equipment

'

'

'

'

'

$55,300,000

$102,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property_Plant_and_Equipment_S

Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) (USD $)

12 Months Ended

3 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

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

Machinery and Equipment [Member]

Machinery and Equipment [Member]

Building and Building Improvements [Member]

Building and Building Improvements [Member]

Land [Member]

Land [Member]

Stillwater Mine [Member]

Stillwater Mine [Member]

East Boulder Mine [Member]

East Boulder Mine [Member]

Processing Facilities and Other [Member]

Processing Facilities and Other [Member]

Marathon Properties [Member]

Marathon Properties [Member]

Marathon Properties [Member]

Construction in Progress [Member]

Construction in Progress [Member]

Construction in Progress [Member]

Construction in Progress [Member]

Construction in Progress [Member]

Construction in Progress [Member]

Construction in Progress [Member]

Construction in Progress [Member]

Property, Plant and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment, gross

$320,137,000

$292,610,000

'

$138,351,000

$107,957,000

$160,076,000

$145,347,000

$8,592,000

$8,418,000

$5,818,000

$18,515,000

$1,057,000

$888,000

$5,841,000

$11,247,000

'

$402,000

$238,000

Less accumulated depreciation

-195,406,000

-169,933,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total property, plant, and equipment

124,731,000

122,677,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment charge

461,755,000

0

0

'

'

'

'

'

'

'

'

'

'

'

'

171,400,000

800,000

'

Property, plant and equipment, estimated fair market value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,900,000

'

Property_Plant_and_Equipment_S1

Property, Plant and Equipment (Schedule Of Capital Expenditures) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]	'	'	'
Total capital outlay	$129,029	$112,748	$101,940
Acquired by capital lease transactions	0	-677	0
Total cash paid	129,029	112,071	101,940
Stillwater Mine [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Total capital outlay	83,548	86,541	69,168
East Boulder Mine [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Total capital outlay	24,979	10,443	18,888
Marathon project [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Total capital outlay	12,380	8,319	13,470
Altar Property [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Total capital outlay	101	18	63
Other Mine [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Total capital outlay	$8,021	$7,427	$351

Asset_Retirement_Obligation_Na

Asset Retirement Obligation (Narrative) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Short-term Debt [Line Items]	'
Current financial guarantee requirements	$33.30

Asset_Retirement_Obligation_Ch

Asset Retirement Obligation (Changes In Asset Retirement Obligation) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'	'	'
Beginning Balance	$7,965	$7,331	$6,747
Accretion expense	689	634	584
Ending Balance	8,654	7,965	7,331
Stillwater Mine [Member]	'	'	'
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'	'	'
Beginning Balance	7,381	6,794	6,253
Accretion expense	639	587	541
Ending Balance	8,020	7,381	6,794
East Boulder Mine [Member]	'	'	'
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'	'	'
Beginning Balance	584	537	494
Accretion expense	50	47	43
Ending Balance	$634	$584	$537

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	12 Months Ended										3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2000	Dec. 31, 2013	Mar. 31, 2008	Dec. 31, 2013	Dec. 31, 2012	Oct. 31, 2012	Dec. 31, 2013
				8% Series 2000 [Member]	8% Series 2000 [Member]	1.875% convertible debentures [Member]	1.875% convertible debentures [Member]	1.75% convertible debentures [Member]	1.75% convertible debentures [Member]	1.75% convertible debentures [Member]	Marathon Properties [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Mineral properties and mine development, and property, plant and equipment, net	'	'	'	'	'	'	'	'	'	'	$228,600,000
Impairment charge	461,755,000	0	0	'	'	'	'	'	'	'	171,400,000
Mineral properties and mine development, and property, plant and equipment, estimated fair market value	'	'	'	'	'	'	'	'	'	'	57,200,000
Debt instrument, face amount	'	'	'	$30,000,000	$30,000,000	'	$181,500,000	'	'	$396,750,000	'
Debt instrument, stated rate	'	'	'	8.00%	'	1.88%	1.88%	1.75%	1.75%	1.75%	'

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	$209,338	$261,983
Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Mutual funds	604	1,817
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Mutual funds	604	1,817
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Mutual funds	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Mutual funds	0	0
Fair Value, Measurements, Recurring [Member] | Federal agency notes [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	97,585	124,715
Fair Value, Measurements, Recurring [Member] | Federal agency notes [Member] | Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Federal agency notes [Member] | Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	97,585	124,715
Fair Value, Measurements, Recurring [Member] | Federal agency notes [Member] | Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	111,753	137,268
Fair Value, Measurements, Recurring [Member] | Commercial paper [Member] | Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Commercial paper [Member] | Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	111,753	137,268
Fair Value, Measurements, Recurring [Member] | Commercial paper [Member] | Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Investments	$0	$0

Fair_Value_Measurements_Financ1

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On A Nonrecurring Basis) (Details) (Fair Value, Measurements, Nonrecurring [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Marathon mineral properties and property, plant and equipment	$57,272	'
Exempt facility industrial revenue bonds	30,050	29,968
Long-term investments	1,021	2,922
Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Marathon mineral properties and property, plant and equipment	0	'
Exempt facility industrial revenue bonds	0	0
Long-term investments	1,021	2,922
Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Marathon mineral properties and property, plant and equipment	0	'
Exempt facility industrial revenue bonds	0	0
Long-term investments	0	0
Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Marathon mineral properties and property, plant and equipment	57,272	'
Exempt facility industrial revenue bonds	30,050	29,968
Long-term investments	0	0
1.875% convertible debentures [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	2,245	166,292
1.875% convertible debentures [Member] | Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	0	0
1.875% convertible debentures [Member] | Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	2,245	166,292
1.875% convertible debentures [Member] | Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	0	0
1.75% convertible debentures [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	308,574	302,466
1.75% convertible debentures [Member] | Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	0	0
1.75% convertible debentures [Member] | Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	308,574	302,466
1.75% convertible debentures [Member] | Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible debentures	$0	$0

Related_Parties_Details

Related Parties (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2013
	Mitsubishi Corporation [Member]	Mitsubishi Corporation [Member]	Stillwater Canada, Inc. [Member]	Stillwater Canada, Inc. [Member]
				Mitsubishi Corporation [Member]
Related Party Transaction [Line Items]	'	'	'	'
Third party ownership interest in company subsidiary	'	'	25.00%	25.00%
PGM sales to related party	$296.60	$206.40	'	'

Commitments_and_Contingencies_1

Commitments and Contingencies (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Entity
Related Party Transaction [Line Items]	'	'	'
Number of entities company has contracted with	2	'	'
Total rental expense for cancelable and non-cancelable operating leases	$2.30	$2.40	$1.50
Active labor force covered by collective bargaining arrangements expiring on June 1, 2015 [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Percentage of active labor force covered by collective bargaining agreements	60.00%	'	'
Active labor force covered by collective bargaining arrangements expiring on December 1, 2015 [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Percentage of active labor force covered by collective bargaining agreements	19.00%	'	'

Commitments_and_Contingencies_2

Commitments and Contingencies (Future Minimum Lease Payments For Operating Leases) (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'
2014	$474
2015	217
2016	146
2017	130
Total	$967

Commitments_and_Contingencies_3

Commitments and Contingencies (Percentage Of Total Revenues From Significant Customers) (Details)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenue, Major Customer [Line Items]	'		'		'
Concentration Risk, Percentage	69.00%		71.00%		64.00%
Percentage Of Total Revenues, Minimum Limit	10.00%		'		'
Revenues [Member] | Customer Concentration Risk [Member] | Customer A [Member]	'		'		'
Revenue, Major Customer [Line Items]	'		'		'
Concentration Risk, Percentage	29.00%		26.00%		28.00%
Revenues [Member] | Customer Concentration Risk [Member] | Customer B [Member]	'		'		'
Revenue, Major Customer [Line Items]	'		'		'
Concentration Risk, Percentage	14.00%		17.00%		0.00%	[1]
Revenues [Member] | Customer Concentration Risk [Member] | Customer C [Member]	'		'		'
Revenue, Major Customer [Line Items]	'		'		'
Concentration Risk, Percentage	14.00%		0.00%	[1]	19.00%
Revenues [Member] | Customer Concentration Risk [Member] | Customer D [Member]	'		'		'
Revenue, Major Customer [Line Items]	'		'		'
Concentration Risk, Percentage	12.00%		18.00%		17.00%
Revenues [Member] | Customer Concentration Risk [Member] | Customer E [Member]	'		'		'
Revenue, Major Customer [Line Items]	'		'		'
Concentration Risk, Percentage	0.00%	[1]	10.00%		0.00%	[1]
[1]	The “—” symbol represents less than 10% of total revenues

Quarterly_Data_Unaudited_Detai

Quarterly Data (Unaudited) (Details) (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
Quarterly Financial Information Disclosure [Abstract]	'		'		'		'		'	'	'	'	'	'	'
Revenue	$242,360		$280,007		$266,491		$250,648		$203,374	$181,044	$212,775	$203,051	$1,039,506	$800,244	$905,969
Depletion, depreciation and amortization	14,689		15,342		14,003		15,283		14,374	14,107	14,862	14,672	59,317	58,015	62,378
Operating income	-153,099		-258,456		-4,292		19,224		18,597	9,645	13,627	1,767	-396,623	43,636	155,206
Net income	-108,736		-201,984		-5,657		14,304		16,876	12,803	18,797	5,940	-270,206	55,045	144,295
Comprehensive income (loss) attributable to common stockholders	-78,169		-201,276		-5,313		14,657		17,116	13,497	19,046	6,248	-270,101	55,907	144,186
Basic earnings (loss) per share attributable to common stockholders	($0.65)	[1]	($1.69)	[1]	($0.04)	[1]	$0.12	[1]	$0.14	$0.11	$0.17	$0.05	($2.28)	$0.47	$1.36
Diluted earnings (loss) per share attributable to common stockholders	($0.65)	[1]	($1.69)	[1]	($0.04)	[1]	$0.12	[1]	$0.13	$0.11	$0.17	$0.05	($2.28)	$0.46	$1.30
Revision to net income for recognition of deferred tax benefit	'		'		'		'		'	'	'	'	($108,545)	($5,960)	$0
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