U.S. Silica (SLCA) 10-Q 30 Jul 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 25, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Entity Registrant Name	'U.S. Silica Holdings, Inc.	'
Entity Central Index Key	'0001524741	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	53,847,267

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$105,974	$78,256
Short-term investments	75,101	74,980
Accounts receivable, net	108,452	75,207
Inventories, net	58,650	64,212
Prepaid expenses and other current assets	8,936	6,347
Deferred income taxes, net	18,582	17,737
Income tax deposits	5,074	0
Total current assets	380,769	316,739
Property, plant and mine development, net	441,450	442,116
Debt issuance costs, net	4,815	5,255
Goodwill	68,403	68,403
Trade names	10,436	10,436
Customer relationships, net	5,915	6,120
Other assets	11,073	14,392
Total assets	922,861	863,461
Current Liabilities:	'	'
Book overdraft	3,466	4,659
Accounts payable	52,826	37,376
Dividends payable	6,770	6,709
Accrued liabilities	13,020	10,823
Accrued interest	41	41
Current portion of long-term debt	3,489	3,488
Income tax payable	0	1,037
Total current liabilities	79,612	64,133
Long-term debt	366,218	367,963
Liability for pension and other post-retirement benefits	34,431	36,802
Deferred income taxes, net	74,203	71,318
Other long-term obligations	14,913	13,951
Total liabilities	569,377	554,167
Stockholders’ Equity:	'	'
Preferred stock	0	0
Common stock	538	534
Additional paid-in capital	185,155	174,799
Retained earnings	171,540	137,978
Treasury stock, at cost	'	'
Accumulated other comprehensive loss	-3,749	-4,017
Total stockholders’ equity	353,484	309,294
Total liabilities and stockholders’ equity	$922,861	$863,461

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]	'	'	'	'
Sales	$205,801	$129,828	$385,896	$252,139
Cost of goods sold (excluding depreciation, depletion and amortization)	132,417	80,297	259,187	154,709
Operating expenses	'	'	'	'
Selling, general and administrative	19,267	10,099	34,712	22,503
Depreciation, depletion and amortization	10,341	8,890	19,930	17,168
Total operating expenses	29,608	18,989	54,642	39,671
Operating income	43,776	30,542	72,067	57,759
Other (expense) income	'	'	'	'
Interest expense	-4,013	-3,535	-7,821	-7,111
Other income, net, including interest income	221	63	259	185
Total other (expenses) income	-3,792	-3,472	-7,562	-6,926
Income before income taxes	39,984	27,070	64,505	50,833
Income tax expense	-11,330	-6,878	-17,480	-13,364
Net income	$28,654	$20,192	$47,025	$37,469
Earnings per share:	'	'	'	'
Basic (in usd per share)	$0.53	$0.38	$0.88	$0.71
Diluted (in usd per share)	$0.53	$0.38	$0.87	$0.70

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$28,654	$20,192	$47,025	$37,469
Other comprehensive income:	'	'	'	'
Unrealized gain (loss) on derivatives (net of tax of ($22) and $101 for the three months ended June 30, 2014 and 2013, respectively, and ($34) and $152 for the six months ended June 30, 2014 and 2013, respectively)	-34	157	-53	238
Unrealized gain (loss) on investments (net of tax of ($5) and $0 for the three months ended June 30, 2014 and 2013, respectively, and $14 and $0 for the six months ended June 30, 2014 and 2013, respectively)	-6	0	23	0
Pension and other post-retirement benefits liability adjustment (net of tax of $95 and $217 for the three months ended June 30, 2014 and 2013, respectively, and $190 and $434 for the six months ended June 30, 2014 and 2013, respectively)	149	341	298	682
Comprehensive income	$28,763	$20,690	$47,293	$38,389

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Tax expenses on unrealized gain (loss) on derivatives	($22)	$101	($34)	$152
Tax expense (benefit) on unrealized gain (loss) on investments	-5	0	14	0
Tax expenses on pension and other post-retirement benefits liability adjustment	$95	$217	$190	$434

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings (Deficit)	Accumulated Other Comprehensive Income (Loss)
Balance at December 31, 2013 at Dec. 31, 2013	$309,294,000	$534,000	$0	$174,799,000	$137,978,000	($4,017,000)
Net income	47,025,000	'	'	'	47,025,000	'
Other comprehensive income, net of tax	268,000	'	'	'	'	268,000
Proceeds from options exercised	4,710,000	4,000	534,000	4,172,000	'	'
Shares withheld for employee taxes related to vested restricted stock	-534,000	'	-534,000	'	'	'
Cash dividends declared ($ 0.25 per share of common stock)	-13,463,000	'	'	'	-13,463,000	'
Equity-based compensation	3,383,000	'	'	3,383,000	'	'
Excess tax benefit from equity-based compensation	2,801,000	'	'	2,801,000	'	'
Balance at June 30, 2014 at Jun. 30, 2014	$353,484,000	$538,000	$0	$185,155,000	$171,540,000	($3,749,000)

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	6 Months Ended
	Jun. 30, 2014
Common stock cash dividend declared, per share	$0.25

Condensed_Consolidated_Stateme5

Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Operating activities:	'	'
Net income	$47,025	$37,469
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	19,930	17,168
Debt issuance amortization	439	262
Original issue discount amortization	131	84
Deferred income taxes	2,042	3,056
Deferred revenue	0	-4,285
Loss on disposal of property, plant and equipment	79	47
Equity-based compensation	3,383	1,383
Excess tax benefit from equity-based compensation	-2,801	-185
Other	3,184	-3,190
Changes in assets and liabilities:	'	'
Accounts receivable	-33,926	-2,220
Inventories	5,562	-12,355
Prepaid expenses and other current assets	-2,659	1,228
Income taxes	-3,310	-22,292
Accounts payable and accrued liabilities	17,647	-6,925
Accrued interest	0	146
Liability for pension and other post-retirement benefits	-1,504	774
Net cash provided by operating activities	55,222	10,165
Investing activities:	'	'
Capital expenditures	-18,011	-31,213
Proceeds from sale of property, plant and equipment	0	81
Net cash used in investing activities	-18,011	-31,132
Financing activities:	'	'
Dividends paid	-13,402	0
Proceeds from options exercised	4,710	2,164
Excess tax benefit from equity-based compensation	2,801	185
Shares withheld to pay taxes due upon vesting of restricted stock	0	-145
Tax payments related to shares withheld for vested restricted stock	-534	0
Repayment of long-term debt	-1,875	-1,300
Change in book overdraft	-1,193	-377
Change in revolving credit facility	0	6,866
Principal payments on capital lease obligations	0	-380
Net cash provided by (used in) financing activities	-9,493	7,013
Net increase (decrease) in cash and cash equivalents	27,718	-13,954
Cash and cash equivalents, beginning of period	78,256	61,022
Cash and cash equivalents, end of period	105,974	47,068
Cash paid during the period for:	'	'
Interest	7,668	6,468
Taxes	$18,920	$33,185

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Basis of Presentation and Consolidation
	The accompanying Condensed Consolidated Financial Statements (the “Financial Statements”) of U.S. Silica Holdings, Inc. (“Holdings,” and together with its subsidiaries “we,” “us” or the “Company”) included in this Quarterly Report on Form 10-Q , have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X issued by the U.S. Securities and Exchange Commission (“SEC”). They do not contain certain information included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2013; therefore, the interim Condensed Consolidated Financial Statements should be read in conjunction with that Annual Report on Form 10-K. In the opinion of management, all adjustments necessary for a fair presentation of the Financial Statements have been included. Such adjustments are of a normal, recurring nature. We have reclassified certain immaterial amounts in the prior years’ assets section of the consolidated balance sheets and operating activities section of the consolidated statement of cash flows to conform to the current year presentation. These reclassifications had no effect on previously reported total assets and net cash flows from operations.
	In order to make this report easier to read, we refer throughout to (i) our Condensed Consolidated Balance Sheets as our “Balance Sheets,” (ii) our Condensed Consolidated Statements of Operations as our “Income Statements,” and (iii) our Condensed Consolidated Statements of Cash Flows as our “Cash Flows.”
	Unaudited Interim Financial Statements
	The accompanying Balance Sheet as of June 30, 2014; the Income Statements for the three and six months ended June 30, 2014 and 2013; the Condensed Consolidated Statements of Comprehensive Income for the three and six months ended June 30, 2014 and 2013; the Condensed Consolidated Statements of Stockholders' Equity for the six months ended June 30, 2014; the Cash Flows for the six months ended June 30, 2014 and 2013; and other information disclosed in the related notes are unaudited. The Balance Sheet as of December 31, 2013 was derived from our audited consolidated financial statements as included in our 2013 Annual Report.
	Use of Estimates and Assumptions
	The preparation of the Financial Statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the related disclosure of contingent assets and liabilities at the date of the Financial Statements and the reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions relate to mineral reserves that are the basis for future cash flow estimates utilized in impairment calculations and units-of-production amortization calculations; environmental, reclamation and closure obligations; estimates of recoverable minerals; estimates of allowance for doubtful accounts; estimates of fair value for certain reporting units and asset impairments (including impairments of goodwill and other long-lived assets); write-downs of inventory to net realizable value; equity-based compensation expense; post-employment, post-retirement and other employee benefit liabilities; valuation allowances for deferred tax assets; reserves for contingencies and litigation; and the fair value and accounting treatment of financial instruments including derivative instruments. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Accordingly, actual results may differ significantly from these estimates under different assumptions or conditions.
	Recently Issued Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board ("FASB") issued an Accounting Standards Update, Revenue from Contracts with Customers, which supersedes previous revenue recognition guidance. The new standard requires that a company recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the company expects to receive in exchange for those goods or services. Companies will need to use more judgment and estimates than under the guidance currently in effect, including estimating the amount of variable revenue to recognize over each identified performance obligations. Additional disclosures will be required to help users of financial statements understand the nature, amount and timing of revenue and cash flows arising from contracts. The new standard will become effective beginning with the first quarter 2017 and can be adopted either retrospectively to each prior reporting period presented or as a cumulative effect adjustment as of the date of adoption. We are currently evaluating the impact of adopting this new guidance on the consolidated financial statements.

Earnings_Per_Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	EARNINGS PER SHARE
	Basic earnings per common share is computed by dividing income available to common stockholders by the weighted average number of common shares outstanding for the period. Diluted earnings per common share is computed similarly to basic income per common share except that the weighted average number of common shares outstanding is increased to include the number of additional common shares that would have been outstanding if the potentially dilutive common shares had been issued. In accordance with the applicable accounting guidance for calculating earnings per share, we did not include in our calculation of diluted earnings per share for the applicable periods stock options where the exercise prices were greater than the average market prices. We did not have any stock options that were antidilutive for the three and six months ended June 30, 2014 and 2013, respectively.
		Three Months Ended						Six Months Ended
		June 30,						June 30,
		2014			2013			2014			2013
	Net income	$	28,654		$	20,192		$	47,025		$	37,469
	Less: net income allocated to outstanding restricted stockholders	(54		)	(23		)	(96		)	(42		)
	Net income allocated to common stockholders	$	28,600		$	20,169		$	46,929		$	37,427
	Weighted-average common stock
	Outstanding	53,733			52,948			53,619			52,948
	Outstanding assuming dilution	54,262			53,227			54,163			53,227

Capital_Structure_and_Accumula

Capital Structure and Accumulated Comprehensive Income	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Capital Structure and Accumulated Comprehensive Income	'
	CAPITAL STRUCTURE AND ACCUMULATED COMPREHENSIVE INCOME
	Common Stock
	Our Amended and Restated Certificate of Incorporation, authorizes up to 500,000,000 shares of common stock, par value of $0.01. Subject to the rights of holders of any series of preferred stock, all of the voting power of the stockholders of Holdings shall be vested in the holders of the common stock. There were 53,847,267 shares of common stock issued and outstanding at June 30, 2014. As of June 30, 2013, there were 53,069,657 shares issued and outstanding.
	In 2014, our Board of Directors declared quarterly cash dividends as follows:
	Dividends per Common Share				Declaration Date		Record Date		Payable Date
	$	0.125			February 6, 2014		March 14, 2014		April 1, 2014
	$	0.125			April 25, 2014		June 13, 2014		July 3, 2014
	All dividends were paid as scheduled.
	Any determination to pay dividends and other distributions in cash, stock, or property by Holdings in the future will be at the discretion of our Board of Directors and will be dependent on then-existing conditions, including our business conditions, our financial condition, results of operations, liquidity, capital requirements, contractual restrictions including restrictive covenants contained in our debt agreements, and other factors. Additionally, because we are a holding company, our ability to pay dividends on our common stock may be limited by restrictions on the ability of our subsidiaries to pay dividends or make distributions to us, including restrictions under the terms of the agreements governing our indebtedness.
	Preferred Stock
	Our Amended and Restated Certificate of Incorporation authorizes our Board of Directors to issue up to 10,000,000 shares, in the aggregate, of preferred stock, par value of $0.01 in one or more series, to fix the powers, preferences and other rights of such series, and any qualifications, limitations or restrictions thereof, including the dividend rate, conversion rights, voting rights, redemption rights and liquidation preference, and to fix the number of shares to be included in any such series, without any further vote or action by our stockholders.
	There are no shares of preferred stock issued or outstanding at June 30, 2014 and 2013. At present, we have no plans to issue any preferred stock.
	Share Repurchase Program
	On June 11, 2012, our Board of Directors authorized us to repurchase up to $25.0 million of our common stock. The authorization was initially for a period of 18 months, concluding on December 11, 2013, but on November 4, 2013, our Board of Directors extended the repurchase program through December 11, 2014. We are authorized to repurchase, from time to time, shares of our outstanding common stock on the open market or in privately negotiated transactions. Stock repurchases will be funded using our available liquidity. The timing and amount of stock repurchases will depend on a variety of factors, including the market conditions as well as corporate and regulatory considerations. The share repurchase program may be suspended, modified or discontinued at any time and we have no obligation to repurchase any additional amount of our common stock under the program. We intend to make all repurchases in compliance with applicable regulatory guidelines and to administer the plan in accordance with applicable laws, including Rule 10b-18 of the Securities Exchange Act of 1934, as amended. As part of the program, as of June 30, 2014, we have repurchased 100,000 shares of our common stock at an average price of $10.72 and are authorized to repurchase up to an additional $23.9 million of our common stock. As of June 30, 2014, all of the 100,000 shares repurchased to date have been re-issued to satisfy employee option exercises.
	Accumulated Other Comprehensive Income
	Accumulated other comprehensive income (loss) consists of fair value adjustments associated with cash flow hedges and accumulated adjustments for net experience losses and prior service cost related to employee benefit plans. The following table presents the changes in accumulated other comprehensive income by component during the six months ended June 30, 2014:
		For the Six Months Ended June 30, 2014
		Unrealized				Unrealized				Pension and			Total
		gain/(loss)  on				gain/(loss)  on				other
		cash flow hedges				short-term				post-retirement
						investments				benefits liability
	Beginning Balance	$	(79	)		$	(27	)		$	(3,911	)	$	(4,017	)
	Other comprehensive income (loss) before reclassifications	(57		)		23				—			(34		)
	Amounts reclassed from accumulated other comprehensive income	4				—				298			302
	Ending Balance	$	(132	)		$	(4	)		$	(3,613	)	$	(3,749	)
	Amounts reclassed from accumulated other comprehensive income (loss) related to cash flow hedges category are included in interest expense in our Income Statements and amounts reclassed related to pension and other post-retirement benefits liability category are included in the computation of net periodic pension costs, respectively, at their before tax amounts.

Accounts_Receivable

Accounts Receivable	6 Months Ended
	Jun. 30, 2014
Receivables [Abstract]	'
Accounts Receivable	'
	ACCOUNTS RECEIVABLE
	At June 30, 2014 and December 31, 2013, accounts receivable consisted of the following:
		June 30,			December 31,
		2014			2013
	Trade receivables	$	110,279		$	76,223
	Less: Allowance for doubtful accounts	(3,057		)	(2,376		)
	Net trade receivables	107,222			73,847
	Other receivables	1,230			1,360
	Total accounts receivable	$	108,452		$	75,207
	The increase of $34.1 million in trade receivables is mainly driven by the sales increase for the six months ended June 30, 2014.

Inventories

Inventories	6 Months Ended
	Jun. 30, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	INVENTORIES
	At June 30, 2014 and December 31, 2013, inventories consisted of the following:
		June 30,		December 31,
		2014		2013
	Supplies	$	16,394	$	15,576
	Raw materials and work in process	9,029		11,728
	Finished goods	33,227		36,908
	Total inventories	$	58,650	$	64,212
	Inventories include raw stockpiles and silica and other industrial sand available for shipment, as well as spare parts and supplies for routine facilities maintenance. We value inventory at the lower of cost or market. Cost is determined using the first-in, first-out and average cost methods.

Property_Plant_and_Mine_Develo

Property, Plant and Mine Development	6 Months Ended
	Jun. 30, 2014
Property, Plant and Equipment [Abstract]	'
Property, Plant and Mine Development	'
	PROPERTY, PLANT AND MINE DEVELOPMENT
	At June 30, 2014 and December 31, 2013, property, plant and mine development consisted of the following:
		June 30,			December 31,
		2014			2013
	Mining property and mine development	$	164,609		$	164,609
	Asset retirement cost	7,997			7,275
	Land	25,797			25,738
	Land improvements	31,959			31,093
	Buildings	36,619			36,311
	Machinery and equipment	270,316			263,304
	Furniture and fixtures	1,347			1,131
	Construction-in-progress	35,422			25,974
		574,066			555,435
	Accumulated depletion, depreciation and amortization	(132,616		)	(113,319		)
	Total property, plant and mine development, net	$	441,450		$	442,116
	Depreciation expense, including depletion and amortization, recognized during the six months ended June 30, 2014 and 2013 was $19.9 million and $17.2 million, respectively. The amount of interest costs capitalized in property, plant and equipment was $474 and $259 for the six months ended June 30, 2014 and 2013, respectively. As of June 30, 2014, we hold no assets under a capital lease obligation.

Debt

Debt	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Debt	'
	DEBT
	At June 30, 2014 and December 31, 2013, debt consisted of the following:
		June 30,			December 31,
		2014			2013
	Senior secured credit facility:
	Revolver expiring July 23, 2018 (4.75% at June 30, 2014 and December 31, 2013)	$	—		$	—
	Term loan facility - final maturity July 23, 2020 (4% at June 30, 2014 and December 31, 2013), net of unamortized original issue discount of $1,543 and $1,674, respectively	369,707			371,451
	Total debt	369,707			371,451
	Less: current portion	(3,489		)	(3,488		)
	Total long-term portion of debt	$	366,218		$	367,963
	Revolving Line-of-Credit
	We have a $50 million revolving line-of-credit (the “Revolver”), with zero drawn and $3.3 million allocated for letters of credit as of June 30, 2014, leaving $46.7 million available under the Revolver.
	Debt Maturities
	At June 30, 2014, contractual maturities of long-term debt are as follows:
	2014	$	1,744
	2015	3,491
	2016	3,493
	2017	3,495
	2018	3,498
	Thereafter	353,986
		$	369,707
	Our senior secured credit facility is secured by substantially all of our assets and a pledge of the equity interests in certain of our subsidiaries. The facility contains covenants that, among other things, govern our ability to create, incur or assume indebtedness and liens, to make acquisitions or investments, to pay dividends and to sell assets. The facility also requires us to maintain a consolidated total net leverage ratio of no more than 3.75:1.00 as of the last day of any fiscal quarter whenever usage of the Revolver (other than certain undrawn letters of credit) exceeds 25% of the Revolver commitment. As of June 30, 2014, we are in compliance with all covenants in accordance with our senior secured credit facility.

Asset_Retirement_Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	ASSET RETIREMENT OBLIGATIONS
	Mine reclamation costs, or future remediation costs for inactive mines, are accrued based on management’s best estimate at the end of each period of the costs expected to be incurred at a site. Such cost estimates include, where applicable, ongoing care, maintenance and monitoring costs. Changes in estimates at inactive mines are reflected in earnings in the period an estimate is revised.
	As of June 30, 2014 and December 31, 2013, we had recorded a liability of $10.4 million and $9.4 million in other long-term obligations related to our asset retirement obligation. Changes in the asset retirement obligation during the six months ended June 30, 2014 and the year ended December 31, 2013, respectively, are as follows:
		June 30,		December 31,
		2014		2013
	Beginning balance	$	9,378	$	6,659
	Payments	—		—
	Accretion	336		456
	Revisions of prior estimates	722		2,263
	Ending balance	$	10,436	$	9,378

Fair_Value_Accounting

Fair Value Accounting	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Accounting	'
	FAIR VALUE ACCOUNTING
	Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:
	Level 1—Quoted prices in active markets for identical assets or liabilities
	Level 2—Observable inputs other than quoted prices in active markets for identical assets and liabilities, quote prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3—Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.
	Cash equivalents
	Due to the short-term maturity, we believe our cash equivalent instruments at June 30, 2014 and December 31, 2013 approximate their reported carrying values.
	Short-Term Investments
	In general, the fair value of our short-term investments is based on quoted prices for similar assets in active markets, or for identical assets or similar assets in markets in which there were fewer transactions (Level 2). Money market mutual funds are based on calculated net asset value and are reported in Level 1. Variable rate demand obligations underwritten and remarketed by a financial institution are priced at par value.
	Long-Term Debt, including current maturities
	We believe that the fair values of our long-term debt, including current maturities, approximates their carrying values and based on their effective interest rates compared to current market rates.
	Derivative Instruments
	The estimated fair value of our derivative assets (interest rate caps) are recorded at each reporting period and are based upon widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative contract. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. We also incorporate credit valuation adjustments to appropriately reflect both our nonperformance risk as well as that of the respective counterparty in the fair value measurements.
	Although we have determined that the majority of the inputs used to value our derivatives fall with Level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default of ourselves and our counterparties. However, as of June 30, 2014, we have assessed that the impact of the credit valuation adjustments on the overall valuation of our derivative positions is not significant. As a result, we have determined that our derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy.
	In accordance with the fair value hierarchy, the following table presents the fair value as of June 30, 2014 of those assets that we measure at fair value on a recurring basis:
		Level 1		Level 2		Total
	Short-term investments	$	340	$	74,761	$	75,101
	Interest rate derivatives	—		16		16
	Net asset	$	340	$	74,777	$	75,117

ShortTerm_Investments

Short-Term Investments	6 Months Ended
	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Short-Term Investments	'
	SHORT-TERM INVESTMENTS
	We have segregated funds into designated accounts with investment brokers who manage our short-term investment portfolio. Those funds are held on an available-for-sale basis and are therefore reported at fair value on the balance sheet.
	The following table summarizes our available-for-sale short-term investments as of June 30, 2014:
		Aggregate		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
	Money market mutual funds	$	340	$	—	$	—		$	340
	Fixed income securities:								—
	Certificates of deposit	26,736		—		(28		)	26,708
	Commercial paper	14,191		15		—			14,206
	Corporate notes and bonds	10,895		1		(1		)	10,895
	Government agencies	13,992		14		—			14,006
	U.S. Treasuries	4,811		—		(6		)	4,805
	Variable Rate Demand Obligations	4,141		—		—			4,141
	Total available-for-sale investments	$	75,106	$	30	$	(35	)	$	75,101
	As of June 30, 2014, we considered the declines in market value of our short-term investment portfolio to be temporary in nature and did not consider any of our investments other-than-temporarily impaired. We typically invest in highly-rated securities, and our investment policy generally limits the amount of credit exposure to any one issuer. The policy requires investments generally to be investment grade, with the primary objective of minimizing the potential risk of principal loss. Fair values were determined for each individual security in the investment portfolio. When evaluating an investment for other-than-temporary impairment, we review factors such as the length of time and extent to which fair value has been below its cost basis, the financial condition of the issuer and any changes thereto, changes in market interest rates, and our intent to sell, or whether it is more likely than not it will be required to sell, the investment before recovery of the investment’s cost basis. As of June 30, 2014, we did not recognize any impairment charges.

Leases

Leases	6 Months Ended
	Jun. 30, 2014
Leases [Abstract]	'
Leases	'
	LEASES
	We are obligated under certain operating leases for railroad cars, office space, mining property, mining/processing equipment and transportation and other equipment. Certain operating lease agreements include options to purchase the equipment for fair market value at the end of the original lease term. Future minimum annual commitments under such operating leases at June 30, 2014 are as follows:
	2014	$	13,125
	2015	27,128
	2016	24,870
	2017	22,608
	2018	21,202
	Thereafter	47,319
	Total future lease commitments	$	156,252
	Expense related to operating leases and rental agreements was $8.2 million and $3.1 million for the three months ended June 30, 2014 and 2013, respectively, and $15.3 million and $6.4 million for the six months ended June 30, 2014 and 2013, respectively. The increase was mainly due to new leases for railroad cars.
	As of June 30, 2014, we have no obligation under a capital lease. We had an obligation under capital lease of $364 as of June 30, 2013, which was paid in full by December 31, 2013.
	In general, the above leases include renewal options and some provide that we pay for all utilities, insurance, taxes and maintenance.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	Our operating subsidiary, U.S. Silica Company (“U.S. Silica”), has been named as a defendant in various product liability claims alleging silica exposure causing silicosis. During the six months ended June 30, 2014, no new claims were brought against U.S. Silica. As of June 30, 2014, there were 87 active silica-related products liability claims pending in which U.S. Silica is a defendant. Although the outcomes of these claims cannot be predicted with certainty, in the opinion of management, the ultimate resolution of these matters will not have a material adverse effect on our financial position or results of operations.
	For periods prior to 1986, U.S. Silica had insurance policies and an indemnity from a former owner that covered silicosis claims. In the fourth quarter of 2012, U.S. Silica settled all rights under the indemnity and its underlying insurance. The settlement was received during first quarter of 2013. As a result of the settlement, the indemnity and related policies are no longer available to U.S. Silica and U.S. Silica will not seek reimbursement for any defense costs or claim payments. Other insurance policies, however, continue to remain available to U.S. Silica.
	We have recorded estimated liabilities for these claims in other long-term obligations as well as estimated recoveries under the remaining insurance policies in other assets on our consolidated balance sheets. As of June 30, 2014 and December 31, 2013, other non-current assets included $313 for insurance for third-party products liability claims and other long-term obligations included $1.6 million in third-party products claims liability.

Pension_and_PostRetirement_Ben

Pension and Post-Retirement Benefits	6 Months Ended
	Jun. 30, 2014
Compensation and Retirement Disclosure [Abstract]	'
Pension and Post-Retirement Benefits	'
	PENSION AND POST-RETIREMENT BENEFITS
	We maintain a single-employer noncontributory defined benefit pension plan covering certain employees. Net pension benefit cost recognized for the three and six months ended June 30, 2014 and 2013 are as follows:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Service cost	$	270		$	320		$	539		$	640
	Interest cost	1,142			1,049			2,285			2,099
	Expected return on plan assets	(1,255		)	(1,265		)	(2,510		)	(2,531		)
	Net amortization and deferral	238			476			476			952
	Net pension benefit costs	$	395		$	580		$	790		$	1,160
	In addition, we provide defined benefit post-retirement health care and life insurance benefits to some employees. Net periodic post-retirement benefit cost recognized for the three and six months ended June 30, 2014 and 2013 are as follows:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Service cost	$	45		$	58		$	90		$	116
	Interest cost	257			252			514			505
	Expected return on plan assets	(1		)	(1		)	(2		)	(2		)
	Net amortization and deferral	—			74			—			148
	Net post-retirement costs	$	301		$	383		$	602		$	767
	We contributed $1.9 million and $2.6 million to the qualified pension plan during the three and six months ended June 30, 2014 , respectively. We did not contribute during the same periods in 2013. Total expected employer funding contributions during the fiscal year ending December 31, 2014 are $4.6 million for the pension plan and $1.2 million for the post-retirement medical and life plan.

Obligations_under_Guarantees

Obligations under Guarantees	6 Months Ended
	Jun. 30, 2014
Guarantees [Abstract]	'
Obligations under Guarantees	'
	OBLIGATIONS UNDER GUARANTEES
	We have indemnified Travelers Casualty and Surety Company of America (“Travelers”) against any loss Travelers may incur in the event that holders of surety bonds, issued on behalf of us by Travelers, execute the bonds. As of June 30, 2014, Travelers had $8.5 million in bonds outstanding for us. The majority of these bonds ($8.2 million) relate to reclamation requirements issued by various governmental authorities. Reclamation bonds remain outstanding until the mining area is reclaimed and the authority issues a formal release. The remaining bonds relate to such indefinite purposes as licenses, permits, and tax collection.
	U.S. Silica is the contingent guarantor of Kanawha Rail Corporation’s (“KRC”) obligations as lessee of 199 covered hopper railroad cars, which are used by U.S. Silica to ship sand to its customers. KRC’s obligation as lessee includes paying monthly rent of $66 thousand until June 30, 2015, maintaining the cars, paying for any cars damaged or destroyed, and indemnifying all other parties to the lease transaction against liabilities including any loss of certain tax benefits. By separate agreement between U.S. Silica and KRC, KRC may, upon the occurrence of certain events, assign the lease obligations to U.S. Silica, but none of these events have occurred.

Segment_Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Segment Reporting	'
	SEGMENT REPORTING
	Our business is organized into two reportable segments, Oil & Gas Proppants and Industrial & Specialty Products, based on end markets. The reportable segments are consistent with how management views the markets that we serve and the financial information reviewed by the chief operating decision maker. We manage our Oil & Gas Proppants and Industrial & Specialty Products businesses as components of an enterprise for which separate information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assess performance.
	An operating segment’s performance is primarily evaluated based on segment contribution margin, which excludes certain corporate costs not associated with the operations of the segment. These corporate costs are separately stated below and include costs that are related to functional areas such as operations management, corporate purchasing, accounting, treasury, information technology, legal and human resources. We believe that segment contribution margin, as defined above, is an appropriate measure for evaluating the operating performance of our segments. However, this measure should be considered in addition to, not a substitute for, or superior to, income from operations or other measures of financial performance prepared in accordance with generally accepted accounting principles. The other accounting policies of each of the two reporting segments are the same as those in the summary of significant accounting policies.
	In the Oil & Gas Proppants segment, we serve the oil and gas recovery market by providing fracturing sand, or “frac sand,” which is pumped down oil and natural gas wells to prop open rock fissures and increase the flow rate of oil and natural gas from the wells.
	The Industrial & Specialty Products segment consists of over 250 products and materials used in a variety of industries including, container glass, fiberglass, specialty glass, flat glass, building products, fillers and extenders, foundry products, chemicals, recreation products and filtration products.
	The following table presents sales and segment contribution margin for the reporting segments and other operating results not allocated to the reported segments for the three and six months ended June 30, 2014 and 2013:
		Three Months Ended						Six Months Ended
		June 30,						June 30,
		2014			2013			2014			2013
	Sales:
	Oil & Gas Proppants	$	149,331		$	77,672		$	279,915		$	151,254
	Industrial & Specialty Products	56,470			52,156			105,981			100,885
	Total Sales	205,801			129,828			385,896			252,139
	Segment contribution margin:
	Oil & Gas Proppants	57,060			35,475			98,688			71,637
	Industrial & Specialty Products	17,615			15,358			30,802			28,604
	Total segment contribution margin	74,675			50,833			129,490			100,241
	Operating activities excluded from segment cost of goods sold	(1,291		)	(1,302		)	(2,781		)	(2,811		)
	Selling, general and administrative	(19,267		)	(10,099		)	(34,712		)	(22,503		)
	Depreciation, depletion and amortization	(10,341		)	(8,890		)	(19,930		)	(17,168		)
	Interest expense	(4,013		)	(3,535		)	(7,821		)	(7,111		)
	Other income, net, including interest income	221			63			259			185
	Income (loss) before income taxes	$	39,984		$	27,070		$	64,505		$	50,833
	Asset information, including capital expenditures and depreciation, depletion, and amortization, by segment is not included in reports used by management in its monitoring of performance and, therefore, is not reported by segment. Goodwill of $68.4 million has been allocated to these segments with $47.7 million assigned to Oil & Gas Proppants and $20.7 million to Industrial & Specialty Products.

Subsequent_Events_Notes

Subsequent Events (Notes)	6 Months Ended
	Jun. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	SUBSEQUENT EVENTS
	On July 3, 2014 we paid a cash dividend of $0.125 per share to common stockholders of record on June 13, 2014, as had been declared by our Board of Directors on April 25, 2014.
	On July 3, 2014, we received an advance of $100 million from a customer. The deposit gives the customer the right to purchase certain products for a fixed price at certain minimum volumes. The customer has an unsecured promissory note on their deposit. The note has a stated interest rate of 4.9% compounded quarterly. The obligations and related interest are reduced as shipments occur with a portion of the sales price being received in cash and a smaller noncash portion reducing first any accrued interest and then, to the extent available, any outstanding principal. As such, the note does not require any payments in cash. The note matures on December 31, 2019, and can be repaid at any time without penalty at our discretion.
	On July 16, 2014, we entered into a stock purchase agreement to acquire all of the outstanding shares of Cadre Services Inc., a regional sand mining company based in Voca, Texas, for approximately $98.0 million in cash. Closing is expected by the end of July 2014. We are not planning to incur any additional debt in order to close this transaction.
	On July 25, 2014, our Board of Directors declared a cash dividend of $0.125 per share to common stock holders of record on September 15, 2014, and payable on October 3, 2014.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation and Consolidation	'
	Basis of Presentation and Consolidation
	The accompanying Condensed Consolidated Financial Statements (the “Financial Statements”) of U.S. Silica Holdings, Inc. (“Holdings,” and together with its subsidiaries “we,” “us” or the “Company”) included in this Quarterly Report on Form 10-Q , have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X issued by the U.S. Securities and Exchange Commission (“SEC”). They do not contain certain information included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2013; therefore, the interim Condensed Consolidated Financial Statements should be read in conjunction with that Annual Report on Form 10-K. In the opinion of management, all adjustments necessary for a fair presentation of the Financial Statements have been included. Such adjustments are of a normal, recurring nature. We have reclassified certain immaterial amounts in the prior years’ assets section of the consolidated balance sheets and operating activities section of the consolidated statement of cash flows to conform to the current year presentation. These reclassifications had no effect on previously reported total assets and net cash flows from operations.
	In order to make this report easier to read, we refer throughout to (i) our Condensed Consolidated Balance Sheets as our “Balance Sheets,” (ii) our Condensed Consolidated Statements of Operations as our “Income Statements,” and (iii) our Condensed Consolidated Statements of Cash Flows as our “Cash Flows.”
Unaudited Interim Financial Statements	'
	Unaudited Interim Financial Statements
	The accompanying Balance Sheet as of June 30, 2014; the Income Statements for the three and six months ended June 30, 2014 and 2013; the Condensed Consolidated Statements of Comprehensive Income for the three and six months ended June 30, 2014 and 2013; the Condensed Consolidated Statements of Stockholders' Equity for the six months ended June 30, 2014; the Cash Flows for the six months ended June 30, 2014 and 2013; and other information disclosed in the related notes are unaudited. The Balance Sheet as of December 31, 2013 was derived from our audited consolidated financial statements as included in our 2013 Annual Report.
Use of Estimates and Assumptions	'
	Use of Estimates and Assumptions
	The preparation of the Financial Statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the related disclosure of contingent assets and liabilities at the date of the Financial Statements and the reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions relate to mineral reserves that are the basis for future cash flow estimates utilized in impairment calculations and units-of-production amortization calculations; environmental, reclamation and closure obligations; estimates of recoverable minerals; estimates of allowance for doubtful accounts; estimates of fair value for certain reporting units and asset impairments (including impairments of goodwill and other long-lived assets); write-downs of inventory to net realizable value; equity-based compensation expense; post-employment, post-retirement and other employee benefit liabilities; valuation allowances for deferred tax assets; reserves for contingencies and litigation; and the fair value and accounting treatment of financial instruments including derivative instruments. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Accordingly, actual results may differ significantly from these estimates under different assumptions or conditions.
Recently Adopted Accounting Pronouncements	'
	Recently Issued Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board ("FASB") issued an Accounting Standards Update, Revenue from Contracts with Customers, which supersedes previous revenue recognition guidance. The new standard requires that a company recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the company expects to receive in exchange for those goods or services. Companies will need to use more judgment and estimates than under the guidance currently in effect, including estimating the amount of variable revenue to recognize over each identified performance obligations. Additional disclosures will be required to help users of financial statements understand the nature, amount and timing of revenue and cash flows arising from contracts. The new standard will become effective beginning with the first quarter 2017 and can be adopted either retrospectively to each prior reporting period presented or as a cumulative effect adjustment as of the date of adoption. We are currently evaluating the impact of adopting this new guidance on the consolidated financial statements.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Schedule of Basic and Diluted Earnings Per Share	'
	Basic earnings per common share is computed by dividing income available to common stockholders by the weighted average number of common shares outstanding for the period. Diluted earnings per common share is computed similarly to basic income per common share except that the weighted average number of common shares outstanding is increased to include the number of additional common shares that would have been outstanding if the potentially dilutive common shares had been issued. In accordance with the applicable accounting guidance for calculating earnings per share, we did not include in our calculation of diluted earnings per share for the applicable periods stock options where the exercise prices were greater than the average market prices. We did not have any stock options that were antidilutive for the three and six months ended June 30, 2014 and 2013, respectively.
		Three Months Ended						Six Months Ended
		June 30,						June 30,
		2014			2013			2014			2013
	Net income	$	28,654		$	20,192		$	47,025		$	37,469
	Less: net income allocated to outstanding restricted stockholders	(54		)	(23		)	(96		)	(42		)
	Net income allocated to common stockholders	$	28,600		$	20,169		$	46,929		$	37,427
	Weighted-average common stock
	Outstanding	53,733			52,948			53,619			52,948
	Outstanding assuming dilution	54,262			53,227			54,163			53,227

Capital_Structure_and_Accumula1

Capital Structure and Accumulated Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Schedule of Quarterly Cash Dividends	'
	In 2014, our Board of Directors declared quarterly cash dividends as follows:
	Dividends per Common Share				Declaration Date		Record Date		Payable Date
	$	0.125			February 6, 2014		March 14, 2014		April 1, 2014
	$	0.125			April 25, 2014		June 13, 2014		July 3, 2014
Changes in Accumulated Other Comprehensive Income	'
	The following table presents the changes in accumulated other comprehensive income by component during the six months ended June 30, 2014:
		For the Six Months Ended June 30, 2014
		Unrealized				Unrealized				Pension and			Total
		gain/(loss)  on				gain/(loss)  on				other
		cash flow hedges				short-term				post-retirement
						investments				benefits liability
	Beginning Balance	$	(79	)		$	(27	)		$	(3,911	)	$	(4,017	)
	Other comprehensive income (loss) before reclassifications	(57		)		23				—			(34		)
	Amounts reclassed from accumulated other comprehensive income	4				—				298			302
	Ending Balance	$	(132	)		$	(4	)		$	(3,613	)	$	(3,749	)

Accounts_Receivable_Tables

Accounts Receivable (Tables)	6 Months Ended
	Jun. 30, 2014
Receivables [Abstract]	'
Schedule of Accounts Receivable	'
	At June 30, 2014 and December 31, 2013, accounts receivable consisted of the following:
		June 30,			December 31,
		2014			2013
	Trade receivables	$	110,279		$	76,223
	Less: Allowance for doubtful accounts	(3,057		)	(2,376		)
	Net trade receivables	107,222			73,847
	Other receivables	1,230			1,360
	Total accounts receivable	$	108,452		$	75,207

Inventories_Tables

Inventories (Tables)	6 Months Ended
	Jun. 30, 2014
Inventory Disclosure [Abstract]	'
Schedule of Inventories	'
	At June 30, 2014 and December 31, 2013, inventories consisted of the following:
		June 30,		December 31,
		2014		2013
	Supplies	$	16,394	$	15,576
	Raw materials and work in process	9,029		11,728
	Finished goods	33,227		36,908
	Total inventories	$	58,650	$	64,212

Property_Plant_and_Mine_Develo1

Property, Plant and Mine Development (Tables)	6 Months Ended
	Jun. 30, 2014
Property, Plant and Equipment [Abstract]	'
Schedule of Property, Plant and Mine Development	'
	At June 30, 2014 and December 31, 2013, property, plant and mine development consisted of the following:
		June 30,			December 31,
		2014			2013
	Mining property and mine development	$	164,609		$	164,609
	Asset retirement cost	7,997			7,275
	Land	25,797			25,738
	Land improvements	31,959			31,093
	Buildings	36,619			36,311
	Machinery and equipment	270,316			263,304
	Furniture and fixtures	1,347			1,131
	Construction-in-progress	35,422			25,974
		574,066			555,435
	Accumulated depletion, depreciation and amortization	(132,616		)	(113,319		)
	Total property, plant and mine development, net	$	441,450		$	442,116

Debt_Tables

Debt (Tables)	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Debt	'
	At June 30, 2014 and December 31, 2013, debt consisted of the following:
		June 30,			December 31,
		2014			2013
	Senior secured credit facility:
	Revolver expiring July 23, 2018 (4.75% at June 30, 2014 and December 31, 2013)	$	—		$	—
	Term loan facility - final maturity July 23, 2020 (4% at June 30, 2014 and December 31, 2013), net of unamortized original issue discount of $1,543 and $1,674, respectively	369,707			371,451
	Total debt	369,707			371,451
	Less: current portion	(3,489		)	(3,488		)
	Total long-term portion of debt	$	366,218		$	367,963
Schedule of Contractual Maturities of Debt	'
	At June 30, 2014, contractual maturities of long-term debt are as follows:
	2014	$	1,744
	2015	3,491
	2016	3,493
	2017	3,495
	2018	3,498
	Thereafter	353,986
		$	369,707

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of Changes in Asset Retirement Obligation	'
	Changes in the asset retirement obligation during the six months ended June 30, 2014 and the year ended December 31, 2013, respectively, are as follows:
		June 30,		December 31,
		2014		2013
	Beginning balance	$	9,378	$	6,659
	Payments	—		—
	Accretion	336		456
	Revisions of prior estimates	722		2,263
	Ending balance	$	10,436	$	9,378

Fair_Value_Accounting_Tables

Fair Value Accounting (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Measure at Fair Value on Recurring Basis	'
	In accordance with the fair value hierarchy, the following table presents the fair value as of June 30, 2014 of those assets that we measure at fair value on a recurring basis:
		Level 1		Level 2		Total
	Short-term investments	$	340	$	74,761	$	75,101
	Interest rate derivatives	—		16		16
	Net asset	$	340	$	74,777	$	75,117

ShortTerm_Investments_Tables

Short-Term Investments (Tables)	6 Months Ended
	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Summary of Available-for-Sale Short-Term Investments	'
	We have segregated funds into designated accounts with investment brokers who manage our short-term investment portfolio. Those funds are held on an available-for-sale basis and are therefore reported at fair value on the balance sheet.
	The following table summarizes our available-for-sale short-term investments as of June 30, 2014:
		Aggregate		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
	Money market mutual funds	$	340	$	—	$	—		$	340
	Fixed income securities:								—
	Certificates of deposit	26,736		—		(28		)	26,708
	Commercial paper	14,191		15		—			14,206
	Corporate notes and bonds	10,895		1		(1		)	10,895
	Government agencies	13,992		14		—			14,006
	U.S. Treasuries	4,811		—		(6		)	4,805
	Variable Rate Demand Obligations	4,141		—		—			4,141
	Total available-for-sale investments	$	75,106	$	30	$	(35	)	$	75,101

Leases_Tables

Leases (Tables)	6 Months Ended
	Jun. 30, 2014
Leases [Abstract]	'
Future Minimum Annual Commitments under Operating Leases	'
	Future minimum annual commitments under such operating leases at June 30, 2014 are as follows:
	2014	$	13,125
	2015	27,128
	2016	24,870
	2017	22,608
	2018	21,202
	Thereafter	47,319
	Total future lease commitments	$	156,252

Pension_and_PostRetirement_Ben1

Pension and Post-Retirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2014
Compensation and Retirement Disclosure [Abstract]	'
Summarizes Information about Pension and Post-Retirement Benefit Plans	'
	Net pension benefit cost recognized for the three and six months ended June 30, 2014 and 2013 are as follows:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Service cost	$	270		$	320		$	539		$	640
	Interest cost	1,142			1,049			2,285			2,099
	Expected return on plan assets	(1,255		)	(1,265		)	(2,510		)	(2,531		)
	Net amortization and deferral	238			476			476			952
	Net pension benefit costs	$	395		$	580		$	790		$	1,160
	In addition, we provide defined benefit post-retirement health care and life insurance benefits to some employees. Net periodic post-retirement benefit cost recognized for the three and six months ended June 30, 2014 and 2013 are as follows:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Service cost	$	45		$	58		$	90		$	116
	Interest cost	257			252			514			505
	Expected return on plan assets	(1		)	(1		)	(2		)	(2		)
	Net amortization and deferral	—			74			—			148
	Net post-retirement costs	$	301		$	383		$	602		$	767

Segment_Reporting_Tables

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Presentation of Sales and Segment Contribution Margin for Reporting Segments and Other Operating Results	'
	The following table presents sales and segment contribution margin for the reporting segments and other operating results not allocated to the reported segments for the three and six months ended June 30, 2014 and 2013:
		Three Months Ended						Six Months Ended
		June 30,						June 30,
		2014			2013			2014			2013
	Sales:
	Oil & Gas Proppants	$	149,331		$	77,672		$	279,915		$	151,254
	Industrial & Specialty Products	56,470			52,156			105,981			100,885
	Total Sales	205,801			129,828			385,896			252,139
	Segment contribution margin:
	Oil & Gas Proppants	57,060			35,475			98,688			71,637
	Industrial & Specialty Products	17,615			15,358			30,802			28,604
	Total segment contribution margin	74,675			50,833			129,490			100,241
	Operating activities excluded from segment cost of goods sold	(1,291		)	(1,302		)	(2,781		)	(2,811		)
	Selling, general and administrative	(19,267		)	(10,099		)	(34,712		)	(22,503		)
	Depreciation, depletion and amortization	(10,341		)	(8,890		)	(19,930		)	(17,168		)
	Interest expense	(4,013		)	(3,535		)	(7,821		)	(7,111		)
	Other income, net, including interest income	221			63			259			185
	Income (loss) before income taxes	$	39,984		$	27,070		$	64,505		$	50,833

Earnings_Per_Share_Schedule_of

Earnings Per Share - Schedule of Basic and Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income	$28,654	$20,192	$47,025	$37,469
Less: net income allocated to outstanding restricted stockholders	-54	-23	-96	-42
Net income allocated to common stockholders	$28,600	$20,169	$46,929	$37,427
Weighted-average common stock	'	'	'	'
Outstanding (in shares)	53,733	52,948	53,619	52,948
Outstanding assuming dilution (in shares)	54,262	53,227	54,163	53,227

Earnings_Per_Share_Earnings_Pe

Earnings Per Share Earnings Per Share - Phantom (Details) (Employee Stock Options)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Employee Stock Options	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Stock options that were antidilutive	0	0	0	0

Capital_Structure_and_Accumula2

Capital Structure and Accumulated Comprehensive Income - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended	6 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 11, 2012	Mar. 31, 2014	Jun. 30, 2014	Jun. 30, 2013
Capital Structure And Accumulated Comprehensive Income (Loss)	'	'	'	'
Preferred stock issued	'	'	0	0
Common stock, shares outstanding	'	'	53,847,267	53,069,657
Preferred stock, shares outstanding	'	'	0	0
Common Stock	'	'	'	'
Capital Structure And Accumulated Comprehensive Income (Loss)	'	'	'	'
Common stock authorized, shares	'	'	500,000,000	'
Common stock, par value	'	'	$0.01	'
Common stock issued	'	'	53,847,267	53,069,657
Authorization to repurchase common stock	$25	'	'	'
Common stock repurchase authorization period	'	'	'18 months	'
Common stock repurchase authorization period, conclusion date	'	'	11-Dec-14	'
Number of repurchased shares, common stock	'	100,000	'	'
Repurchased common stock, average price	'	$10.72	'	'
Remaining authorized repurchase of common stock amount	'	$23.90	'	'
Re-issued shares to satisfy employee option exercises	'	'	100,000	'
Preferred Stock	'	'	'	'
Capital Structure And Accumulated Comprehensive Income (Loss)	'	'	'	'
Preferred stock, shares authorized	'	'	10,000,000	'
Preferred stock, par value	'	'	$0.01	'
Preferred stock issued	'	'	0	'

Capital_Structure_and_Accumula3

Capital Structure and Accumulated Comprehensive Income - Schedule of Quarterly Cash Dividends (Details) (USD $)	3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014
Equity [Abstract]	'	'
Quarterly cash dividend declared	$0	$0
Dividend declared date	25-Apr-14	6-Feb-14
Dividend declared, record date	13-Jun-14	14-Mar-14
Dividend declared, payable date	'	1-Apr-14

Capital_Structure_and_Accumula4

Capital Structure and Accumulated Comprehensive Income - Changes in Accumulated Other Comprehensive Income (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'
Beginning Balance	($4,017)
Other comprehensive income (loss) before reclassifications	-34
Amounts reclassed from accumulated other comprehensive income	302
Ending Balance	-3,749
Unrealized Gains and Losses on Cash Flow Hedges	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'
Beginning Balance	-79
Other comprehensive income (loss) before reclassifications	-57
Amounts reclassed from accumulated other comprehensive income	4
Ending Balance	-132
Unrealized Gain/(Loss) on Short-Term Investments	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'
Beginning Balance	-27
Other comprehensive income (loss) before reclassifications	23
Amounts reclassed from accumulated other comprehensive income	0
Ending Balance	-4
Pension and Other Postretirement Benefits Liability	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'
Beginning Balance	-3,911
Other comprehensive income (loss) before reclassifications	0
Amounts reclassed from accumulated other comprehensive income	298
Ending Balance	($3,613)

Accounts_Receivable_Additional

Accounts Receivable - Additional Information (Detail) (USD $)	Jun. 30, 2014
In Millions, unless otherwise specified
Receivables [Abstract]	'
Increase in accounts receivable mainly due to increased sales	$34.10

Accounts_Receivable_Schedule_o

Accounts Receivable - Schedule of Accounts Receivable (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Receivables [Abstract]	'	'
Trade receivables	$110,279	$76,223
Less: Allowance for doubtful accounts	-3,057	-2,376
Net trade receivables	107,222	73,847
Other receivables	1,230	1,360
Total accounts receivable	$108,452	$75,207

Inventories_Schedule_of_Invent

Inventories - Schedule of Inventories (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Supplies	$16,394	$15,576
Raw materials and work in process	9,029	11,728
Finished goods	33,227	36,908
Total inventories	$58,650	$64,212

Property_Plant_and_Mine_Develo2

Property, Plant and Mine Development - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Property, Plant and Equipment [Abstract]	'	'	'	'
Depreciation expense, including depletion and amortization	$10,341,000	$8,890,000	$19,930,000	$17,168,000
Interest costs capitalized in property, plant and equipment	'	'	474,000	259,000
Capital lease obligation	$0	'	$0	'

Property_Plant_and_Mine_Develo3

Property, Plant and Mine Development - Schedule of Property, Plant and Mine Development (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment	'	'
Property, plant and mine development	$574,066	$555,435
Accumulated depletion, depreciation and amortization	-132,616	-113,319
Total property, plant and mine development, net	441,450	442,116
Mining Property And Mine Development	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	164,609	164,609
Asset Retirement Cost	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	7,997	7,275
Land	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	25,797	25,738
Land Improvements	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	31,959	31,093
Buildings	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	36,619	36,311
Machinery and Equipment	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	270,316	263,304
Furniture and Fixtures	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	1,347	1,131
Construction-in-Progress	'	'
Property, Plant and Equipment	'	'
Property, plant and mine development	$35,422	$25,974

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014
Short-term Debt	'
Credit facility consolidated total net leverage ratio	0.0375
Net leverage ratio, credit facility threshold (percentage)	25.00%
Revolving Line-of-Credit	'
Short-term Debt	'
Available borrowing base	50,000,000
Amount drawn from borrowing base	0
Amount allocated for letters of credit	3,300,000
Amount available for general corporate use under this revolving credit agreement	46,700,000

Debt_Schedule_of_Debt_Detail

Debt - Schedule of Debt (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Line of Credit Facility	'	'
Total debt	$369,707	$371,451
Less: current portion	-3,489	-3,488
Total long-term portion of debt	366,218	367,963
Revolving Line-of-Credit	'	'
Line of Credit Facility	'	'
Line of credit, amount outstanding	0	0
Senior Secured Credit Facility	'	'
Line of Credit Facility	'	'
Line of credit, amount outstanding	$369,707	$371,451

Debt_Schedule_of_Contractual_M

Debt - Schedule of Contractual Maturities of Debt (Detail) (USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'
2014	$1,744
2015	3,491
2016	3,493
2017	3,495
2018	3,498
Thereafter	353,986
Debt, Total	$369,707

Debt_Phantom_Detail

Debt - Phantom (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Revolving Line-of-Credit	'	'
Line of Credit Facility	'	'
Credit facility, maturity date	23-Jul-18	'
Credit facility, interest rate	4.75%	4.75%
Senior Secured Credit Facility	'	'
Line of Credit Facility	'	'
Credit facility, maturity date	23-Jul-20	'
Credit facility, interest rate	4.00%	4.00%
Term loan facility unamortized original issue discount	1,543	1,674

Asset_Retirement_Obligations_A

Asset Retirement Obligations - Additional Information (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Asset Retirement Obligation Disclosure [Abstract]	'	'	'
Asset Retirement Obligation	$10,436	$9,378	$6,659

Asset_Retirement_Obligations_S

Asset Retirement Obligations - Schedule of Changes in Asset Retirement Obligation (Detail) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]	'	'
Beginning balance	$9,378	$6,659
Payments	0	0
Accretion	336	456
Revisions of prior estimates	722	2,263
Ending balance	$10,436	$9,378

Fair_Value_Accounting_Schedule

Fair Value Accounting - Schedule of Measure at Fair Value on Recurring Basis (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure	'	'
Short-term investments	$75,101	$74,980
Measured at Fair Value on Recurring Basis	'	'
Defined Benefit Plan Disclosure	'	'
Short-term investments	75,101	'
Interest rate derivatives	16	'
Net asset	75,117	'
Measured at Fair Value on Recurring Basis | Level 1	'	'
Defined Benefit Plan Disclosure	'	'
Short-term investments	340	'
Interest rate derivatives	0	'
Net asset	340	'
Measured at Fair Value on Recurring Basis | Level 2	'	'
Defined Benefit Plan Disclosure	'	'
Short-term investments	74,761	'
Interest rate derivatives	16	'
Net asset	$74,777	'

ShortTerm_Investments_Addition

Short-Term Investments - Additional Information (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Impairment charges	$0

ShortTerm_Investments_Schedule

Short-Term Investments - Schedule of Available-for-Sale Short-Term Investments (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	$75,106	'
Gross Unrealized Gains	30	'
Gross Unrealized Losses	-35	'
Short-term investments	75,101	74,980
Money Market Mutual Funds	'	'
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	340	'
Gross Unrealized Gains	0	'
Gross Unrealized Losses	0	'
Fair Value	340	'
Certificates Of Deposit	'	'
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	26,736	'
Gross Unrealized Gains	0	'
Gross Unrealized Losses	-28	'
Fair Value	26,708	'
Commercial Paper	'	'
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	14,191	'
Gross Unrealized Gains	15	'
Gross Unrealized Losses	0	'
Fair Value	14,206	'
Corporate Notes And Bonds	'	'
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	10,895	'
Gross Unrealized Gains	1	'
Gross Unrealized Losses	-1	'
Fair Value	10,895	'
Government Agencies	'	'
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	13,992	'
Gross Unrealized Gains	14	'
Gross Unrealized Losses	0	'
Fair Value	14,006	'
U.S. Treasuries	'	'
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	4,811	'
Gross Unrealized Gains	0	'
Gross Unrealized Losses	-6	'
Fair Value	4,805	'
Variable Rate Demand Obligations	'	'
Schedule of Available-for-sale Securities	'	'
Aggregate Cost	4,141	'
Gross Unrealized Gains	0	'
Gross Unrealized Losses	0	'
Fair Value	$4,141	'

Leases_Additional_Information_

Leases - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Leases [Abstract]	'	'	'	'
Expense related to operating leases and rental agreements	$8,200,000	$3,100,000	$15,300,000	$6,400,000
Capital lease obligation	$0	$364,000	$0	$364,000

Leases_Future_Minimum_Annual_C

Leases - Future Minimum Annual Commitments under Operating Leases (Detail) (USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Leases [Abstract]	'
2014	$13,125
2015	27,128
2016	24,870
2017	22,608
2018	21,202
Thereafter	47,319
Total future lease commitments	$156,252

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
	claim
Insurance [Abstract]	'	'
New claims filed	0	'
Products liability claims outstanding	87	'
Third-party products claims liability under insurance in other assets	$313,000	$313,000
Third-party products claims liability under insurance in other long-term obligations	$1,600,000	$1,600,000

Pension_and_PostRetirement_Ben2

Pension and Post-Retirement Benefits - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2014
Pension Benefits	'	'
Defined Benefit Plan Disclosure	'	'
Defined Benefit Plan, Contributions by Employer	$1.90	$2.60
Defined Benefit Plan, Expected Contributions in Current Fiscal Year	'	4.6
Post-retirement Benefits	'	'
Defined Benefit Plan Disclosure	'	'
Employer contributions for the post-retirement medical and life plan	'	$1.20

Pension_and_PostRetirement_Ben3

Pension and Post-Retirement Benefits - Summarizes Information about Pension and Post-Retirement Benefit Plans (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pension Benefits	'	'	'	'
Pension Plans, Postretirement and Other Employee Benefits [Line Items]	'	'	'	'
Service cost	$270,000	$320,000	$539,000	$640,000
Interest cost	1,142,000	1,049,000	2,285,000	2,099,000
Expected return on plan assets	-1,255,000	-1,265,000	-2,510,000	-2,531,000
Net amortization and deferral	238,000	476,000	476,000	952,000
Net pension benefit costs	395,000	580,000	790,000	1,160,000
Post-retirement Benefits	'	'	'	'
Pension Plans, Postretirement and Other Employee Benefits [Line Items]	'	'	'	'
Service cost	45,000	58,000	90,000	116,000
Interest cost	257,000	252,000	514,000	505,000
Expected return on plan assets	-1,000	-1,000	-2,000	-2,000
Net amortization and deferral	0	74,000	0	148,000
Net pension benefit costs	$301,000	$383,000	$602,000	$767,000

Obligations_Under_Guarantees_A

Obligations Under Guarantees - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014
	railroad_car
Travelers Casualty and Surety Company | Surety Bonds	'
Loss Contingencies	'
Surety bonds outstanding	$8,500,000
Travelers Casualty and Surety Company | Reclamation Bonds	'
Loss Contingencies	'
Bonds related to reclamation requirements	8,200,000
Kanawha Rail Corporation | Leased Railroad Hopper Cars	'
Loss Contingencies	'
Number of railroad cars	199
Payment of monthly rent	$66,000

Segment_Reporting_Additional_I

Segment Reporting - Additional Information (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
	Segment
Segment Reporting Information	'	'
Number of reportable segments	2	'
Goodwill	$68,403	$68,403
Industrial & Specialty Products segment, description	'Over 250 products and materials used in a variety of industries including, container glass, fiberglass, specialty glass, flat glass, building products, fillers and extenders, foundry products, chemicals, recreation products and filtration products.	'
Oil & Gas Proppants	'	'
Segment Reporting Information	'	'
Goodwill	47,700	'
Industrial & Specialty Products	'	'
Segment Reporting Information	'	'
Number of products in Industrial & Specialty segment (over 250)	250	'
Goodwill	$20,700	'

Segment_Reporting_Presentation

Segment Reporting - Presentation of Sales and Segment Contribution Margin for Reporting Segments and Other Operating Results (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information	'	'	'	'	'
Total Sales	$205,801	$129,828	$385,896	$252,139	'
Total segment contribution margin	74,675	50,833	129,490	100,241	'
Operating activities excluded from segment cost of goods sold	-1,291	-1,302	-2,781	-2,811	'
Selling, general and administrative	-19,267	-10,099	-34,712	-22,503	'
Depreciation, depletion and amortization	-10,341	-8,890	-19,930	-17,168	'
Interest expense	-4,013	-3,535	-7,821	-7,111	'
Other income, net, including interest income	221	63	259	185	'
Income before income taxes	39,984	27,070	64,505	50,833	'
Short-term investments	75,101	'	75,101	'	74,980
Operating Segments | Oil & Gas Proppants	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Total Sales	149,331	77,672	279,915	151,254	'
Total segment contribution margin	57,060	35,475	98,688	71,637	'
Operating Segments | Industrial & Specialty Products	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Total Sales	56,470	52,156	105,981	100,885	'
Total segment contribution margin	$17,615	$15,358	$30,802	$28,604	'

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended		6 Months Ended	0 Months Ended		0 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014	Jul. 03, 2014	Jul. 03, 2014	Jul. 25, 2014	Jul. 16, 2014
				Subsequent Event [Member]	Customer Advance	Dividend Declared	Acquisition of Cadre Services Inc.
Subsequent Event	'	'	'	'	'	'	'
Dividend declared, payable date	'	1-Apr-14	'	3-Jul-14	'	'	'
Dividends, Common Stock, Cash	'	'	$13,463,000	$0.13	'	$0.13	'
Dividend declared, record date	13-Jun-14	14-Mar-14	'	'	'	'	'
Dividend declared date	25-Apr-14	6-Feb-14	'	'	'	'	'
Customer Advances and Deposits	'	'	'	'	100,000,000	'	'
Customer Promissory Note, Interest Rate, Stated Percentage	'	'	'	'	0.049	'	'
Payments to Acquire Businesses, Gross	'	'	'	'	'	'	$98,000,000