BWX (BWXT) 10-K/A 26 Feb 15 2014 FY Annual report (amended) Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Jan. 31, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K/A
Amendment Flag	TRUE
Amendment Description	The sole purpose of this Amendment No. 1 on Form 10-K/A (the "Form 10-K/A") to our Annual Report on Form 10-K for the year ended December 31, 2014 originally filed with the Securities and Exchange Commission on February 25, 2015 (the "Form 10-K"), is to correct the number of shares of our common stock outstanding at January 31, 2015 on the cover page of such Form 10-K. The correct number of shares of our common stock outstanding at January 31, 2015 was 106,710,346. The Form 10-K/A has not been updated for events occurring after the filing of the Form 10-K, and no attempt has been made in this Form 10-K/A to modify or update other disclosures as presented in the original filing of our Form 10-K.
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	BWC
Entity Registrant Name	Babcock & Wilcox Co
Entity Central Index Key	1486957
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		106,710,346
Entity Public Float			$3.60

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
ASSETS
Cash and cash equivalents	$312,969	$346,116
Restricted cash and cash equivalents	54,497	45,945
Investments	4,837	10,748
Accounts receivable - trade, net	430,600	360,323
Accounts receivable - other	44,299	45,480
Contracts in progress	398,373	370,820
Inventories	108,637	113,058
Deferred income taxes	73,479	97,170
Other current assets	46,111	47,764
Total Current Assets	1,473,802	1,437,424
Property, Plant and Equipment	1,167,581	1,126,683
Less accumulated depreciation	730,946	679,604
Net Property, Plant and Equipment	436,635	447,079
Investments	7,606	4,426
Goodwill	379,192	281,708
Deferred Income Taxes	245,766	127,076
Investments in Unconsolidated Affiliates	140,504	184,831
Intangible Assets	110,873	81,521
Other Assets	62,558	45,088
TOTAL	2,856,936	2,609,153
LIABILITIES AND STOCKHOLDERS' EQUITY
Notes payable and current maturities of long-term debt	18,215	4,671
Accounts payable	247,629	319,774
Accrued employee benefits	124,897	163,833
Accrued liabilities - other	97,207	58,192
Advance billings on contracts	255,535	317,771
Accrued warranty expense	53,624	56,436
Income taxes payable	22,529	6,551
Total Current Liabilities	819,636	927,228
Long-term Debt	285,000	225
Accumulated Postretirement Benefit Obligation	58,213	43,194
Environmental Liabilities	56,259	53,391
Pension Liability	563,990	336,878
Other Liabilities	59,637	65,296
Commitments and Contingencies (Note 10)
Stockholders' Equity:
Common stock, par value $0.01 per share, authorized 325,000,000 shares; issued 121,604,332 and 120,536,910 shares at December 31, 2014 and December 31, 2013, respectively	1,216	1,205
Preferred stock, par value $0.01 per share, authorized 75,000,000 shares; no shares issued
Capital in excess of par value	775,393	747,189
Retained earnings	642,489	656,916
Treasury stock at cost, 14,915,776 and 10,068,731 shares at December 31, 2014 and December 31, 2013, respectively	-423,990	-268,971
Accumulated other comprehensive income	3,596	28,348
Stockholders' Equity - The Babcock & Wilcox Company	998,704	1,164,687
Noncontrolling interest	15,497	18,254
Total Stockholders' Equity	1,014,201	1,182,941
TOTAL	$2,856,936	$2,609,153

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	325,000,000	325,000,000
Common stock, shares issued	121,604,332	120,536,910
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	75,000,000	75,000,000
Preferred stock, shares issued	0	0
Treasury stock at cost, shares	14,915,776	10,068,731

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Revenues	$2,923,019	$3,269,208	$3,291,359
Costs and Expenses:
Cost of operations	2,409,376	2,301,648	2,461,205
Research and development costs	73,234	79,226	120,562
Losses on asset disposals and impairments, net	1,081	1,049	1,419
Selling, general and administrative expenses	442,615	379,382	428,293
Special charges for restructuring activities	41,091	39,599
Total Costs and Expenses	2,967,397	2,800,904	3,011,479
Equity in Income of Investees	41,756	68,058	66,709
Operating Income (Loss)	-2,622	536,362	346,589
Other Income (Expense):
Interest income	1,028	1,443	1,491
Interest expense	-7,579	-3,115	-3,735
Other - net	14,639	-17,517	-24,927
Total Other Income (Expense)	8,088	-19,189	-27,171
Income before Provision for Income Taxes	5,466	517,173	319,418
Provision for (Benefit from)Income Taxes	-15,991	184,583	101,861
Net Income	21,457	332,590	217,557
Net Loss Attributable to Noncontrolling Interest	7,931	13,488	10,138
Net Income Attributable to The Babcock & Wilcox Company	$29,388	$346,078	$227,695
Basic:
Net Income Attributable to The Babcock & Wilcox Company	$0.27	$3.09	$1.92
Diluted:
Net Income Attributable to The Babcock & Wilcox Company	$0.27	$3.07	$1.91
Shares used in the computation of earnings per share (Note 18):
Basic	108,477,262	111,901,750	118,418,930
Diluted	108,761,092	112,685,417	119,021,324

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net Income	$21,457	$332,590	$217,557
Other Comprehensive Income:
Currency translation adjustments	-26,905	-2,518	4,284
Derivative financial instruments:
Unrealized gains (losses) arising during the period, net of tax benefit (provision) of $824, $1,518 and $(622), respectively	-2,360	-4,418	1,409
Reclassification adjustment for (gains) losses included in net income, net of tax (benefit) provision of $(559), $(973) and $704, respectively	1,610	2,942	-2,023
Benefit obligations:
Unrecognized losses arising during the period, net of tax benefit of $511, $1,177 and $221, respectively	-840	-1,928	-434
Recognition of benefit plan costs, net of tax benefit of $(1,547), $(1,035) and $(1,159), respectively	3,681	1,975	2,281
Investments:
Unrealized gains arising during the period, net of tax provision of $(75), $(103) and $0, respectively	136	302	431
Reclassification adjustment for gains included in net income, net of tax provision of $61, $30 and $0, respectively	-111	-769	-35
Other Comprehensive Income (Loss)	-24,789	-4,414	5,913
Total Comprehensive Income (Loss)	-3,332	328,176	223,470
Comprehensive Loss Attributable to Noncontrolling Interest	7,968	13,522	10,127
Comprehensive Income Attributable to The Babcock & Wilcox Company	$4,636	$341,698	$233,597

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Tax benefit (provision) of unrealized gains (losses) on derivative financial instruments	$824	$1,518	($622)
Tax (benefit) provision on reclassification adjustment for (gains) losses on derivative financial instruments	-559	-973	704
Tax benefit on unrecognized losses	511	1,177	221
Tax benefit of recognition of benefit plan costs	-1,547	-1,035	-1,159
Tax provision of unrealized gains	-75	-103	0
Tax provision on reclassification adjustment for gain on investment	$61	$30	$0

Consolidated_Statement_of_Stoc

Consolidated Statement of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Capital In Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Stockholders' Equity [Member]	Non-Controlling Interest [Member]
In Thousands, except Share data
Balance at Dec. 31, 2011	$834,973	$1,185	$676,952	$130,890	$26,826	($10,059)	$825,794	$9,179
Balance, Shares at Dec. 31, 2011		118,458,911
Net Income	217,557			227,695			227,695	-10,138
Dividends declared	-9,522			-9,522			-9,522
Defined benefit obligations	1,847				1,847		1,847
Available-for-sale investments	396				396		396
Currency translation adjustments	4,284				4,273		4,273	11
Derivative financial instruments	-614				-614		-614
Exercise of stock options	4,514	3	4,511				4,514
Exercise of stock options, Shares		261,784
Contributions to thrift plan	13,793	5	13,788				13,793
Contributions to thrift plan, shares		549,121
Shares placed in treasury	-99,750					-99,750	-99,750
Stock-based compensation charges	18,009	3	18,006				18,009
Stock-based compensation charges, Shares		338,210
Contribution of in-kind services	17,942							17,942
Distributions to noncontrolling interests	-513							-513
Balance at Dec. 31, 2012	1,002,916	1,196	713,257	349,063	32,728	-109,809	986,435	16,481
Balance, Shares at Dec. 31, 2012		119,608,026
Net Income	332,590			346,078			346,078	-13,488
Dividends declared	-38,225			-38,225			-38,225
Defined benefit obligations	47				47		47
Available-for-sale investments	-467				-467		-467
Currency translation adjustments	-2,518				-2,484		-2,484	-34
Derivative financial instruments	-1,476				-1,476		-1,476
Exercise of stock options	4,930	2	4,928				4,930
Exercise of stock options, Shares		241,561
Contributions to thrift plan	13,939	5	13,934				13,939
Contributions to thrift plan, shares		464,451
Shares placed in treasury	-159,162					-159,162	-159,162
Stock-based compensation charges	15,072	2	15,070				15,072
Stock-based compensation charges, Shares		222,872
Contribution of in-kind services	15,794							15,794
Distributions to noncontrolling interests	-499							-499
Balance at Dec. 31, 2013	1,182,941	1,205	747,189	656,916	28,348	-268,971	1,164,687	18,254
Balance, Shares at Dec. 31, 2013	120,536,910	120,536,910
Net Income	21,457			29,388			29,388	-7,931
Dividends declared	-43,815			-43,815			-43,815
Defined benefit obligations	2,841				2,841		2,841
Available-for-sale investments	25				25		25
Currency translation adjustments	-26,905				-26,868		-26,868	-37
Derivative financial instruments	-750				-750		-750
Exercise of stock options	4,750	2	4,748				4,750
Exercise of stock options, Shares		193,595
Contributions to thrift plan	13,725	4	13,721				13,725
Contributions to thrift plan, shares		436,246
Shares placed in treasury	-155,019					-155,019	-155,019
Stock-based compensation charges	9,740	5	9,735				9,740
Stock-based compensation charges, Shares		437,581
Contribution of in-kind services	5,831							5,831
Distributions to noncontrolling interests	-620							-620
Balance at Dec. 31, 2014	$1,014,201	$1,216	$775,393	$642,489	$3,596	($423,990)	$998,704	$15,497
Balance, Shares at Dec. 31, 2014	121,604,332	121,604,332

Consolidated_Statement_of_Stoc1

Consolidated Statement of Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Dividends declared per share	$0.40	$0.34	$0.08

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$21,457	$332,590	$217,557
Non-cash items included in net income:
Depreciation and amortization	105,798	70,525	69,697
Income of investees, net of dividends	18,763	11,537	-15,115
Losses on asset disposals and impairments	12,543	1,049	1,419
Impairment of USEC investment		19,139	27,000
Gain on exchange of USEC investment	-18,647
In-kind research and development costs	5,831	15,794	17,942
Provision for (benefit from) deferred taxes	-95,697	94,068	43,038
Recognition of (gains) losses for pension and postretirement plans	244,136	-219,915	35,480
Stock-based compensation and thrift plan expense	23,461	29,006	31,797
Excess tax benefits from stock-based compensation	-588	-177	-1,571
Changes in assets and liabilities, net of effects from acquisitions:
Accounts receivable	-50,080	19,726	-52,034
Accounts payable	-81,044	54,895	30,391
Contracts in progress and advance billings on contracts	-98,400	-210,582	32,527
Inventories	5,044	11,971	-16,448
Income taxes	-1,259	-6,364	5,522
Accrued and other current liabilities	18,557	-28,499	-30,553
Pension liability, accrued postretirement benefit obligation and employee benefits	-42,264	-68,961	-168,004
Other, net	7,314	12,084	-43,718
NET CASH PROVIDED BY OPERATING ACTIVITIES	74,925	137,886	184,927
CASH FLOWS FROM INVESTING ACTIVITIES:
Decrease (increase) in restricted cash and cash equivalents	-8,552	15,016	229
Purchases of property, plant and equipment	-76,029	-64,950	-86,635
Acquisition of businesses, net of cash acquired	-127,703		-318
Purchase of intangible assets	-722	-2,200
Purchases of securities	-23,622	-90,836	-268,929
Sales and maturities of securities	40,725	168,879	247,649
Proceeds from asset disposals	997	1,028	580
Proceeds from sale of an unconsolidated affiliate			2,091
Investment in equity and cost method investees	-4,900	-6,884	-6,064
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	-199,806	20,053	-111,397
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of short-term borrowing and long-term debt	-4,539	-211	-4,643
Payment of debt issuance costs	-5,473		-4,902
Borrowings under short-term arrangements	2,967	484	3,815
Borrowings under Credit Agreement	1,156,100
Repayments under Credit Agreement	-856,100
Repurchase of common shares	-149,774	-157,093	-96,774
Dividends paid to common shareholders	-43,469	-38,011	-9,485
Exercise of stock options	4,604	4,275	2,926
Excess tax benefits from stock-based compensation	588	177	1,571
Other	-305	-499	-514
NET CASH (USED IN) PROVIDED BY FINANCING ACTIVITIES	104,599	-190,878	-108,006
EFFECTS OF EXCHANGE RATE CHANGES ON CASH	-12,865	-4,492	2,814
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	-33,147	-37,431	-31,662
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	346,116	383,547	415,209
CASH AND CASH EQUIVALENTS AT END OF PERIOD	312,969	346,116	383,547
Cash paid during the period for:
Interest	6,061	1,790	2,049
Income taxes (net of refunds)	74,734	86,924	83,062
SCHEDULE OF NONCASH INVESTING ACTIVITY:
Accrued capital expenditures included in accounts payable	$7,219	$8,141	$7,902

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	NOTE 1 – BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES
	We have presented the consolidated financial statements of The Babcock & Wilcox Company (“B&W”) in U.S. dollars in accordance with accounting principles generally accepted in the United States (“GAAP”).
	We use the equity method to account for investments in entities that we do not control, but over which we have the ability to exercise significant influence. We generally refer to these entities as “joint ventures.” We have eliminated all intercompany transactions and accounts. We have reclassified certain amounts previously reported to conform to the presentation at December 31, 2014 and for the year ended December 31, 2014. We present the notes to our consolidated financial statements on the basis of continuing operations, unless otherwise stated.
	Unless the context otherwise indicates, “we,” “us” and “our” mean B&W and its consolidated subsidiaries.
	Reportable Segments
	We operate in five reportable segments: Power Generation, Nuclear Operations, Technical Services, Nuclear Energy and mPower. Our reportable segments are further described as follows:
		•		Our Power Generation segment provides advanced fossil and renewable power generation equipment that includes a broad suite of boiler products and environmental systems and related services for power and industrial uses. We specialize in engineering, manufacturing, procurement, and erection of equipment and technologies used in the power generation industry and various other industries, and the provision of related services, including steam generating equipment, proven emissions control systems for environmental regulations, renewable energy solutions (biomass, combined heat and power, waste-to-energy and concentrating solar power), boiler cleaning systems, material transport equipment, fuel handling systems, cogeneration and combined cycle installations, and carbon capture and sequestration technologies. For this full range of product offerings, we offer complete aftermarket, operation and maintenance and construction project services. We provide products and services to electric utilities, municipalities, EPC contractors, architect engineers, independent power producers, international trading firms, electric power cooperatives and state electricity boards. Our markets include electric power generation, industrial, chemical, oil refinery, cement, institutional, municipal and government customers worldwide. We have an extensive North American and global footprint including engineering, design, service, manufacturing, sales, business development, regional service centers, manufacturers’ representatives and joint venture facilities located in more than 30 countries around the globe. Our installed base represents more than 300,000 MW of equivalent steam-generating capacity in more than 800 facilities in over 90 countries.
	Our steam generating equipment operates on a range of traditional fossil fuels including coal, natural gas and oil along with renewable, unconventional and other typical waste fuel streams. We have commercialized many advanced emissions technologies to control nitrogen oxide, sulfur dioxide, sulfur trioxide, coarse and fine particulate matter, mercury, acid gases and other hazardous air emissions.
	On June 20, 2014, we completed the acquisition of MEGTEC Holdings, Inc. (“MEGTEC”). MEGTEC designs, engineers, manufactures and services air pollution control systems and coating/drying equipment for a variety of industrial applications and complements our environmental products and solutions offerings.
		•		Our Nuclear Operations segment manufactures naval nuclear reactors for the U.S. Department of Energy (“DOE”)/National Nuclear Security Administration’s (“NNSA”) Naval Nuclear Propulsion Program, which in turn supplies them to the U.S. Navy for use in submarines and aircraft carriers. Through this segment, we own and operate manufacturing facilities located in Lynchburg, Virginia; Mount Vernon, Indiana; Euclid, Ohio; Barberton, Ohio; and Erwin, Tennessee. The Barberton and Mount Vernon locations specialize in the design and manufacture of heavy components. These two locations are N-Stamp certified by the American Society of Mechanical Engineers (“ASME”), making them two of only a few North American suppliers of large, heavy-walled nuclear components and vessels. The Euclid facility, which is also ASME N-Stamp certified, fabricates electro-mechanical equipment for the U.S. Government, and performs design, manufacturing, inspection, assembly and testing activities. The Lynchburg operations fabricate fuel-bearing precision components that range in weight from a few grams to hundreds of tons. In-house capabilities also include wet chemistry uranium processing, advanced heat treatment to optimize component material properties and a controlled, clean-room environment with the capacity to assemble railcar-size components. Fuel for the naval nuclear reactors is provided by Nuclear Fuel Services, Inc. (“NFS”), one of our wholly owned subsidiaries. Located in Erwin, NFS also converts Cold War-era government stockpiles of highly enriched uranium into material suitable for further processing into commercial nuclear reactor fuel.
		•		Our Technical Services segment provides various services to the U.S. Government, including uranium processing, environmental site restoration services and management and operating services for various U.S. Government-owned facilities. These services are provided to the Department of Defense and the DOE, including the NNSA, the Office of Nuclear Energy, the Office of Science, and the Office of Environmental Management. Through this segment we deliver products and management solutions to nuclear operations and high-consequence manufacturing facilities. A significant portion of this segment’s operations are conducted through joint ventures.
		•		Our Nuclear Energy segment supplies commercial nuclear steam generators and components to nuclear utility customers. B&W has supplied the nuclear industry with more than 1,300 large, heavy components worldwide. This segment is the only heavy nuclear component, N-Stamp certified manufacturer in North America. Our Nuclear Energy segment fabricates pressure vessels, reactors, steam generators, heat exchangers and other auxiliary equipment. This segment also provides specialized engineering services that include structural component design, 3-D thermal-hydraulic engineering analysis, weld and robotic process development and metallurgy and materials engineering. In addition, this segment offers services for nuclear steam generators and balance of plant equipment, as well as nondestructive examination and tooling/repair solutions for other plant systems and components. This segment also offers engineering and licensing services for new nuclear plant designs.
		•		Our mPower segment is designing the B&W mPower™ reactor, a small modular reactor (“SMR”) design generally based on proven light-water nuclear technology. Through our majority-owned joint venture, Generation mPower LLC (“GmP”), we are developing the associated mPower Plant power generating facility, which will use two B&W mPower™ reactors to generate greater than 360 MW within an advanced passively safe and secure plant architecture. As part of this initiative, we were selected to receive funding pursuant to a Cooperative Agreement with the DOE under its Small Modular Reactor Licensing Technical Support Program (the “Funding Program”) for SMR deployment. This Funding Program provided financial assistance for our mPower Plant licensing and engineering development costs associated with SMR design certification and generic design activities. On April 14, 2014, we announced our plans to restructure the mPower program to reduce spending and focus on technology development. Beginning in the third quarter of 2014, we slowed the pace of development and intend to invest no more than $15 million on an annual basis while we continue to search for additional investors in the mPower program. We intend to continue working with the DOE to further the program. At this time, the latest extension to the Cooperative Agreement has expired and the DOE funding has been suspended. If a mutually agreeable plan is not identified, future amounts may not be made available to us under the Funding Program.
	For financial information about our segments, see Note 16 to our consolidated financial statements included in this report.
	Spin-off
	On November 5, 2014, we announced plans to separate our Power Generation business from our Government & Nuclear Operations business, which includes the Nuclear Operations, Technical Services, Nuclear Energy and mPower segments, through a spin-off, creating a new independent, publicly traded company, Babcock & Wilcox Enterprises, Inc. (“BW”). We expect the spin-off will be effective by mid-summer 2015, subject to several customary conditions, including final approval of the transaction by our Board of Directors. Concurrent with the spin-off, the Company will change its name to BWX Technologies, Inc. (“BWXT”). We plan to effect the separation through a tax-free spin-off transaction.
	Use of Estimates
	We use estimates and assumptions to prepare our financial statements in conformity with GAAP. Some of our more significant estimates include our estimate of costs to complete long-term construction contracts, estimates of costs to be incurred to satisfy contractual warranty requirements, estimates of the value of acquired intangible assets and estimates we make in selecting assumptions related to the valuations of our pension and postretirement plans, including the selection of our discount rates, mortality and expected rates of return on our pension plan assets. These estimates and assumptions affect the amounts we report in our financial statements and accompanying notes. Our actual results could differ from these estimates. Variances could result in a material effect on our financial condition and results of operations in future periods.
	Earnings Per Share
	We have computed earnings per common share on the basis of the weighted average number of common shares, and, where dilutive, common share equivalents, outstanding during the indicated periods. We have a number of forms of stock-based compensation, including incentive and non-qualified stock options, restricted stock, restricted stock units and performance shares and performance units, subject to satisfaction of specific performance goals. We include the shares applicable to these plans in dilutive earnings per share when related performance criteria have been met.
	Investments
	Our investment portfolio consists primarily of highly liquid money market instruments. Additionally, we currently hold Centrus Energy Corp. bonds and equities received upon USEC Inc.’s emergence from bankruptcy. Our investments are carried at fair value and are either classified as trading, with unrealized gains and losses reported in earnings, or as available-for-sale, with the unrealized gains and losses, net of tax, reported as a component of accumulated other comprehensive income. We classify investments available for current operations in the consolidated balance sheets as current assets, while we classify investments held for long-term purposes as noncurrent assets. We adjust the amortized cost of debt securities for amortization of premiums and accretion of discounts to maturity. That amortization is included in interest income. We include realized gains and losses on our investments in other – net. The cost of securities sold is based on the specific identification method. We include interest on securities in interest income.
	Foreign Currency Translation
	We translate assets and liabilities of our foreign operations into U.S. dollars at current exchange rates, and we translate income statement items at average exchange rates for the periods presented. We record adjustments resulting from the translation of foreign currency financial statements as a component of accumulated other comprehensive income. We report foreign currency transaction gains and losses in income. We have included in other - net transaction gains (losses) of $1.9 million, $0.5 million and $(0.6) million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Contracts and Revenue Recognition
	We generally recognize contract revenues and related costs on a percentage-of-completion method for individual contracts or combinations of contracts based on work performed, man hours or a cost-to-cost method, as applicable to the product or activity involved. We recognize estimated contract revenue and resulting income based on the measurement of the extent of progress completion as a percentage of the total project. Certain costs may be excluded from the cost-to-cost method of measuring progress, such as significant costs for materials and major third-party subcontractors, if it appears that such exclusion would result in a more meaningful measurement of actual contract progress and resulting periodic allocation of income. We include revenues and related costs so recorded, plus accumulated contract costs that exceed amounts invoiced to customers under the terms of the contracts, in contracts in progress. We include in advance billings on contracts billings that exceed accumulated contract costs and revenues and costs recognized under the percentage-of-completion method. Most long-term contracts contain provisions for progress payments. Our unbilled receivables do not contain an allowance for credit losses as we expect to invoice customers and collect all amounts for unbilled revenues. We review contract price and cost estimates periodically as the work progresses and reflect adjustments proportionate to the percentage-of-completion in income in the period when those estimates are revised. For all contracts, if a current estimate of total contract cost indicates a loss on a contract, the projected loss is recognized in full when determined.
	For contracts as to which we are unable to estimate the final profitability except to assure that no loss will ultimately be incurred, we recognize equal amounts of revenue and cost until the final results can be estimated more precisely. For these deferred profit recognition contracts, we recognize revenue and cost equally and only recognize gross margin when probable and reasonably estimable, which we generally determine to be when the contract is approximately 70% complete. We treat long-term construction contracts that contain such a level of risk and uncertainty that estimation of the final outcome is impractical, except to assure that no loss will be incurred, as deferred profit recognition contracts.
	Our policy is to account for fixed-price contracts under the completed-contract method if we believe that we are unable to reasonably forecast cost to complete at start-up. Under the completed-contract method, income is recognized only when a contract is completed or substantially complete.
	For parts orders and certain aftermarket services activities, we recognize revenues as goods are delivered and work is performed.
	Variations from estimated contract performance could result in material adjustments to operating results for any fiscal quarter or year. We include claims for extra work or changes in scope of work to the extent of costs incurred in contract revenues when we believe collection is probable. In the year ended December 31, 2014, we executed a change order in our Nuclear Operations segment that increased the value of existing contracts by $70.5 million. We recognized $46.4 million of revenue for the cumulative effect of this contract change, as well as $25.8 million in cost of operations for the recognition of the associated costs being recovered.
	In the year ended December 31, 2014, we recorded a contract loss totaling approximately $11.6 million for additional estimated costs to complete our Power Generation segment’s Berlin Station project. These losses are in addition to contract losses recorded on this project of $35.6 million and $16.9 million in 2013 and 2012, respectively. We previously asserted that substantial completion had been achieved on this project in early 2014 and that any further delays to complete this project were the result of the customer’s failure to supply fuel complying with the contract specifications. The customer certified that we achieved substantial completion on the project effective July 19, 2014, following which we believe the customer has no further claims for liquidated damages associated with the delays. See Note 10 for legal proceedings associated with this matter.
	The following represent the components of our contracts in progress and advance billings on contracts included in our consolidated balance sheets:
			December 31,
			2014			2013
			(In thousands)
	Included in Contracts in Progress:
	Costs incurred less costs of revenue recognized		$	183,312		$	150,724
	Revenues recognized less billings to customers			215,061			220,096
	Contracts In Progress		$	398,373		$	370,820
	Included In Advance Billings on Contracts:
	Billings to customers less revenues recognized		$	274,151		$	411,156
	Costs incurred less costs of revenue recognized			(18,616	)		(93,385	)
	Advance Billings on Contracts		$	255,535		$	317,771
	The following amounts represent retainages on contracts:
			December 31,
			2014			2013
			(In thousands)
	Retainages expected to be collected within one year		$	103,867		$	84,389
	Retainages expected to be collected after one year			9,092			12,820
	Total retainages		$	112,959		$	97,209
	We have included retainages expected to be collected in 2015 in accounts receivable – trade, net. Retainages expected to be collected after one year are included in other assets. Of the long-term retainages at December 31, 2014, we anticipate collecting $1.8 million in 2016, $5.9 million in 2017 and $1.4 million in 2018.
	Comprehensive Income
	The components of accumulated other comprehensive income included in stockholders’ equity are as follows:
			December 31,
			2014			2013
			(In thousands)
	Currency translation adjustments		$	11,547		$	38,415
	Net unrealized gain on available-for-sale investments			155			130
	Net unrealized gain (loss) on derivative financial instruments			(123	)		627
	Unrecognized prior service cost on benefit obligations			(7,983	)		(10,824	)
	Accumulated other comprehensive income		$	3,596		$	28,348
	The amounts reclassified out of accumulated other comprehensive income by component and the affected consolidated statements of income line items are as follows:
			Year ended December 31,
			2014			2013			2012
Accumulated Other Comprehensive Income		(In thousands)									Line Item Presented
Component Recognized
Realized (loss) gain on derivative financial instruments		$	620		$	(1,885	)	$	(1,082	)	Revenues
			(2,793	)		(2,174	)		3,833		Cost of operations
			4			144			(24	)	Other-net
			(2,169	)		(3,915	)		2,727		Total before tax
			559			973			(704	)	Provision for Income Taxes
		$	(1,610	)	$	(2,942	)	$	2,023		Net Income
Amortization of prior service cost on benefit obligations		$	(3,433	)	$	(2,813	)	$	(3,271	)	Cost of operations
			(1,795	)		(197	)		(169	)	Selling, general and administrative expenses
			(5,228	)		(3,010	)		(3,440	)	Total before tax
			1,547			1,035			1,159		Provision for Income Taxes
		$	(3,681	)	$	(1,975	)	$	(2,281	)	Net Income
Realized gains on investments		$	172		$	799		$	35		Other-net
			(61	)		(30	)		—		Provision for Income Taxes
		$	111		$	769		$	35		Net Income
Total reclassification for the period		$	(5,180	)	$	(4,148	)	$	(223	)
Warranty Expense
We accrue estimated expense included in cost of operations on our consolidated statements of income to satisfy contractual warranty requirements when we recognize the associated revenue on the related contracts. In addition, we record specific provisions or reductions where we expect the actual warranty costs to significantly differ from the accrued estimates. Such changes could have a material effect on our consolidated financial condition, results of operations and cash flows.
The following summarizes the changes in the carrying amount of accrued warranty expense:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
Balance at beginning of period		$	56,436		$	83,682		$	97,209
Additions			14,993			18,486			20,972
Acquisition of MEGTEC			4,693			—			—
Expirations and other changes			(6,393	)		(24,801	)		(24,766	)
Payments			(14,807	)		(20,250	)		(10,217	)
Translation and other			(1,298	)		(681	)		484
Balance at end of period		$	53,624		$	56,436		$	83,682
Asset Retirement Obligations and Environmental Clean-up Costs
We accrue for future decommissioning of our nuclear facilities that will permit the release of these facilities to unrestricted use at the end of each facility’s life, which is a requirement of our licenses from the NRC. In accordance with the FASB Topic Asset Retirement and Environmental Obligations, we record the fair value of a liability for an asset retirement obligation in the period in which it is incurred. When we initially record such a liability, we capitalize a cost by increasing the carrying amount of the related long-lived asset. Over time, the liability is accreted to its present value each period and the capitalized cost is depreciated over the useful life of the related asset. Upon settlement of a liability, we will settle the obligation for its recorded amount or incur a gain or loss. This topic applies to environmental liabilities associated with assets that we currently operate and are obligated to remove from service. For environmental liabilities associated with assets that we no longer operate, we have accrued amounts based on the estimated costs of clean-up activities for which we are responsible, net of any cost-sharing arrangements. We adjust the estimated costs as further information develops or circumstances change. An exception to this accounting treatment relates to the work we perform for two facilities for which the U.S. Government is obligated to pay substantially all of the decommissioning costs.
Substantially all of our asset retirement obligations relate to the remediation of our nuclear analytical laboratory and the NFS facility in our Nuclear Operations segment. The following table reflects our asset retirement obligations:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
Balance at beginning of period		$	44,771		$	42,366		$	35,885
Costs incurred			—			—			—
Additions/Adjustments			418			(109	)		3,422
Accretion			2,622			2,514			3,059
Balance at end of period		$	47,811		$	44,771		$	42,366
Research and Development
Our research and development activities are related to the development and improvement of new and existing products and equipment, as well as conceptual and engineering evaluation for translation into practical applications. We charge the costs of research and development unrelated to specific contracts as incurred. Substantially all of these costs are in our Power Generation and mPower segments, the majority of which are related to the development of our B&W mPower™ reactor and the associated mPower Plant. Contractual arrangements for customer-sponsored research and development can vary on a case-by-case basis and include contracts, cooperative agreements and grants. Research and development activities totaled $142.8 million, $200.8 million and $173.9 million in the years ended December 31, 2014, 2013 and 2012, respectively. This includes amounts paid for by our customers of $41.8 million, $43.2 million and $53.4 million, in the years ended December 31, 2014, 2013 and 2012, respectively, and DOE funds provided under the Funding Program of $27.8 million and $78.4 million in the years ended December 31, 2014 and 2013, respectively. Amounts provided under the Funding Program in the year ended December 31, 2013 include $21.5 million of pre-award cost reimbursement, $9.7 million of which related to research and development costs incurred in the year ended December 31, 2012.
During the years ended December 31, 2014, 2013 and 2012, we recognized $5.8 million, $15.8 million and $17.9 million, respectively, of non-cash in-kind research and development costs (included above) related to services contributed by our minority partner to GmP, our majority-owned subsidiary formed in 2011 to oversee the program to develop the small modular nuclear power plant based on B&W mPower™ technology.
Pension Plans and Postretirement Benefits
We sponsor various defined benefit pension and postretirement plans covering certain employees of our U.S. and international subsidiaries. We utilize actuarial valuations to calculate the cost and benefit obligations of our pension and postretirement benefits. The actuarial valuations utilize significant assumptions in the determination of our benefit cost and obligations, including assumptions regarding discount rates, expected returns on plan assets, mortality and health care cost trends. We determine our discount rate based on a review of published financial data and discussions with our actuary regarding rates of return on high-quality, fixed-income investments currently available and expected to be available during the period to maturity of our pension and postretirement plan obligations. The expected rate of return on plan assets assumption is based on capital market assumptions of the long-term expected returns for the investment mix of assets currently in the portfolio. The expected rate of return on plan assets is determined to be the weighted average of the nominal returns based on the weightings of the classes within the total asset portfolio. Expected health care cost trends represent expected annual rates of change in the cost of health care benefits and are estimated based on analysis of health care cost inflation. For the year ended December 31, 2014, we adjusted the mortality assumption for our domestic plans to reflect mortality improvements identified by the Society of Actuaries, adjusted for the Company’s experience.
The components of benefit cost related to service cost, interest cost, expected return on plan assets and prior service cost amortization are recorded on a quarterly basis based on actuarial assumptions. In the fourth quarter of each year, or as interim remeasurements are required, we immediately recognize net actuarial gains and losses into earnings as a component of net periodic benefit cost. Recognized net actuarial gains and losses consist primarily of our reported actuarial gains and losses and the difference between the actual return on plan assets and the expected return on plan assets.
We recognize the funded status of each plan as either an asset or a liability in the consolidated balance sheets. The funded status is the difference between the fair value of plan assets and the present value of its benefit obligation, determined on a plan-by-plan basis. Our pension plan assets can include assets that are difficult to value. See Note 7 for a detailed description of our plan assets.
Income Taxes
Income tax expense for federal, foreign, state and local income taxes are calculated on pre-tax income based on current tax law and includes the cumulative effect of any changes in tax rates from those used previously in determining deferred tax assets and liabilities. We record a valuation allowance to reduce our deferred tax assets to the amount that is more likely than not to be realized. We assess deferred taxes and the adequacy of the valuation allowance on a quarterly basis. In the ordinary course of business there is inherent uncertainty in quantifying our income tax positions. We assess our income tax positions and record tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances and information available at the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, we have recorded the largest amount of tax benefit with a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is not more likely than not that a tax benefit will be sustained, no tax benefit has been recognized in the financial statements. We record interest and penalties (net of any applicable tax benefit) related to income taxes as a component of provision for income taxes on our consolidated statements of income.
Inventories
We carry our inventories at the lower of cost or market. We determine cost principally on the first-in, first-out basis, except for certain materials inventories of our Power Generation segment, for which we use the last-in, first-out (“LIFO”) method. We determined the cost of approximately 17% and 18% of our total inventories using the LIFO method at December 31, 2014 and 2013, respectively, and our total LIFO reserve at December 31, 2014 and 2013 was approximately $7.9 million and $7.7 million, respectively. Inventories are summarized below:
		December 31,
		2014			2013
		(In thousands)
Raw Materials and Supplies		$	81,530		$	85,455
Work in Progress			9,831			10,872
Finished Goods			17,276			16,731
Total Inventories		$	108,637		$	113,058
Property, Plant and Equipment
We carry our property, plant and equipment at depreciated cost, less any impairment provisions. We depreciate our property, plant and equipment using the straight-line method over estimated economic useful lives of eight to 33 years for buildings and three to 28 years for machinery and equipment. Our depreciation expense was $92.9 million, $62.2 million and $59.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. We expense the costs of maintenance, repairs and renewals that do not materially prolong the useful life of an asset as we incur them.
Property, plant and equipment is stated at cost and is set forth below:
		December 31,
		2014			2013
		(In thousands)
Land		$	15,506		$	11,718
Buildings			253,338			249,614
Machinery and equipment			827,029			782,633
Property under construction			71,708			82,718
			1,167,581			1,126,683
Less accumulated depreciation			730,946			679,604
Net Property, Plant and Equipment		$	436,635		$	447,079
Investments in Unconsolidated Affiliates
We use the equity method of accounting for affiliates in which we are able to exert significant influence. Currently, substantially all of our material investments in affiliates that are not consolidated are recorded using the equity method. Affiliates in which our investment ownership is less than 20% and where we are unable to exert significant influence are carried at cost.
Goodwill
Goodwill represents the excess of the cost of our acquired businesses over the fair value of the net assets acquired. We perform testing of goodwill for impairment annually. We may elect to perform a qualitative test when we believe that there is sufficient excess fair value over carrying value based on our most recent quantitative assessment, adjusted for relevant events and circumstances that could affect fair value during the current year. If we conclude based on this assessment that it is more likely than not that the reporting unit is not impaired, we do not perform a quantitative impairment test. In all other circumstances, we utilize a two-step quantitative impairment test to identify potential goodwill impairment and measure the amount of any goodwill impairment. The first step of the test compares the fair value of a reporting unit with its carrying amount, including goodwill. If the carrying amount of a reporting unit exceeds its fair value, the second step of the goodwill impairment test is performed to measure the amount of the impairment loss, if any. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill.
The following summarizes the changes in the carrying amount of goodwill:
		Power			Nuclear			Technical			Nuclear		Total
		Generation			Operations			Services			Energy
		(In thousands)
Balance at December 31, 2012		$	103,702		$	118,103		$	45,000		$	13,975	$	280,780
Currency translation adjustments and other			928			—			—			—		928
Balance at December 31, 2013		$	104,630		$	118,103		$	45,000		$	13,975	$	281,708
Purchase price adjustment for acquisition of MEGTEC (Note 2)			108,800			—			—			—		108,800
Currency translation adjustments and other(1)			(4,152	)		(7,164	)		—			—		(11,316	)
Balance at December 31, 2014		$	209,278		$	110,939		$	45,000		$	13,975	$	379,192
-1	Includes adjustments resulting from acquisitions occurring prior to December 31, 2012 of $(7.2) million and changes from foreign currency translation adjustments of $(4.2) million and $0.9 million for the years ended December 31, 2013 and 2012, respectively.
Intangible Assets
Intangible assets are recognized at fair value when acquired. Intangible assets with definite lives are amortized to operating expense using the straight-line method over their estimated useful lives and tested for impairment when events or changes in circumstances indicate that their carrying amounts may not be recoverable. Intangible assets with indefinite lives are not amortized and are subject to annual impairment testing. We may elect to perform a qualitative assessment when testing indefinite lived intangible assets for impairment to determine whether events or circumstances affecting significant inputs related to the most recent quantitative evaluation have occurred, indicating that it is more likely than not that the indefinite lived intangible asset is impaired. Otherwise, we test indefinite lived intangible assets for impairment by quantitatively determining the fair value of the indefinite lived intangible asset and comparing the fair value of the intangible asset to its carrying amount. If the carrying amount of the intangible asset exceeds its fair value, we recognize impairment for the amount of the difference. Our intangible assets are as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
Amortized intangible assets:
Gross cost:
Customer relationships		$	57,539		$	35,383		$	36,644
Acquired backlog			10,600			—			2,979
Tradename			11,457			11,945			11,945
Unpatented technology			8,472			6,422			6,422
Patented technology			2,521			2,521			6,961
All other			9,765			9,755			7,912
Total		$	100,354		$	66,026		$	72,863
Accumulated amortization:
Customer relationships		$	(17,011	)	$	(13,490	)	$	(11,173	)
Acquired backlog			(5,300	)		—			(1,457	)
Tradename			(2,959	)		(8,015	)		(6,422	)
Unpatented technology			(3,442	)		(3,335	)		(2,682	)
Patented technology			(1,122	)		(806	)		(4,235	)
All other			(4,782	)		(3,994	)		(4,343	)
Total		$	(34,616	)	$	(29,640	)	$	(30,312	)
Net amortized intangible assets		$	65,738		$	36,386		$	42,551
Unamortized intangible assets:
NRC category 1 license		$	43,830		$	43,830		$	43,830
Trademarks and trade names			1,305			1,305			1,305
Total unamortized intangible assets		$	45,135		$	45,135		$	45,135
The following summarizes the changes in the carrying amount of intangible assets:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
Balance at beginning of period		$	81,521		$	87,686		$	103,041
Business acquisitions and adjustments			44,972			2,200			(1,746	)
Amortization expense			(12,923	)		(8,324	)		(11,010	)
Impairment charge			(1,730	)		(1,260	)		(3,216	)
Currency translation adjustments and other			(967	)		1,219			617
Balance at end of period		$	110,873		$	81,521		$	87,686
We recognized impairment charges totaling $1.7 million and $1.3 million in the years ended December 31, 2014 and 2013, respectively, related to the cancellation of operations and maintenance services contracts and the sale of a subsidiary in our Power Generation segment.
Estimated amortization expense for the next five fiscal years is as follows (in thousands):
Year Ending December 31,		Amount
2015		$	13,360
2016		$	8,006
2017		$	7,912
2018		$	7,262
2019		$	6,908
Other Non-Current Assets
We have included deferred debt issuance costs in other assets. We amortize deferred debt issuance costs as interest expense over the life of the related debt. The following summarizes the changes in the carrying amount of these assets:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
Balance at beginning of period		$	6,518		$	8,468		$	5,723
Additions			5,473			—			4,902
Interest expense – debt issuance costs			(2,070	)		(1,950	)		(2,157	)
Balance at end of period		$	9,921		$	6,518		$	8,468
Capitalization of Interest Cost
We capitalize interest in accordance with FASB Topic Interest. We incurred total interest of $9.5 million, $4.8 million and $4.9 million in the years ended December 31, 2014, 2013 and 2012, respectively, of which we capitalized $1.9 million, $1.7 million and $1.2 million in the years ended December 31, 2014, 2013 and 2012, respectively.
Cash and Cash Equivalents and Restricted Cash
Our cash equivalents are highly liquid investments, with maturities of three months or less when we purchase them.
We record cash and cash equivalents as restricted when we are unable to freely use such cash and cash equivalents for our general operating purposes. At December 31, 2014, we had restricted cash and cash equivalents totaling $57.2 million, $3.7 million of which was held in restricted foreign cash accounts, $2.7 million of which was held for future decommissioning of facilities (which is included in other assets on our consolidated balance sheets), and $50.8 million of which was held to meet reinsurance reserve requirements of our captive insurer.
Derivative Financial Instruments
Our global operations give rise to exposure to market risks from changes in foreign currency exchange (“FX”) rates. We use derivative financial instruments, primarily FX forward contracts, to reduce the impact of changes in FX rates on our operating results. We use these instruments primarily to hedge our exposure associated with revenues or costs on our long-term contracts that are denominated in currencies other than our operating entities’ functional currencies. We do not hold or issue derivative financial instruments for trading or other speculative purposes.
We enter into derivative financial instruments primarily as hedges of certain firm purchase and sale commitments denominated in foreign currencies. We record these contracts at fair value on our consolidated balance sheets and defer the related gains and losses in stockholders’ equity as a component of accumulated other comprehensive income until the hedged item is recognized in earnings. Any ineffective portion of a derivative’s change in fair value and any portion excluded from the assessment of effectiveness is immediately recognized in other – net on our consolidated statements of income. The gain or loss on a derivative instrument not designated as a hedging instrument is also immediately recognized in earnings. Gains and losses on derivative financial instruments that require immediate recognition are included as a component of other – net in our consolidated statements of income.
Self-Insurance
We have a wholly owned insurance subsidiary that provides employer’s liability, general and automotive liability and workers’ compensation insurance and, from time to time, builder’s risk insurance (within certain limits) to our companies. We may also, in the future, have this insurance subsidiary accept other risks that we cannot or do not wish to transfer to outside insurance companies. Included in other liabilities on our consolidated balance sheets are reserves for self-insurance totaling $32.8 million and $37.8 million at December 31, 2014 and 2013, respectively. The reduction in 2014 was primarily attributable to a change in estimate based on historical loss experience recognized in cost of operations in our consolidated statements of income.
Loss Contingencies
We estimate liabilities for loss contingencies when it is probable that a liability has been incurred and the amount of loss is reasonably estimable. We provide disclosure when there is a reasonable possibility that the ultimate loss will exceed the recorded provision or if such probable loss is not reasonably estimable. We are currently involved in some significant litigation, as discussed in Note 10. Our losses are typically resolved over long periods of time and are often difficult to assess and estimate due to, among other reasons, the possibility of multiple actions by third parties; the attribution of damages, if any, among multiple defendants; plaintiffs, in most cases involving personal injury claims, do not specify the amount of damages claimed; the discovery process may take multiple years to complete; during the litigation process, it is common to have multiple complex unresolved procedural and substantive issues; the potential availability of insurance and indemnity coverages; the wide-ranging outcomes reached in similar cases, including the variety of damages awarded; the likelihood of settlements for de minimus amounts prior to trial; the likelihood of success at trial; and the likelihood of success on appeal. Consequently, it is possible future earnings could be affected by changes in our assessments of the probability that a loss has been incurred in a material pending litigation against us and/or changes in our estimates related to such matters.
Stock-Based Compensation
We expense stock-based compensation in accordance with FASB Topic Compensation – Stock Compensation. Under this topic, the fair value of equity-classified awards, such as restricted stock, performance shares and stock options, is determined on the date of grant and is not remeasured. The fair value of liability-classified awards, such as cash-settled stock appreciation rights, restricted stock units and performance units, is determined on the date of grant and is remeasured at the end of each reporting period through the date of settlement. Grant date fair values for restricted stock, restricted stock units, performance shares and performance units are determined using the closing price of our common stock on the date of grant. Grant date fair values for stock options and stock appreciation rights are determined using a Black-Scholes option-pricing model (“Black-Scholes”). For performance shares or units granted in the year ended December 31, 2014 that contain a Relative Total Shareholder Return vesting criteria, we utilize a Monte Carlo simulation to determine the grant date fair value, which determines the probability of satisfying the market condition included in the award. The determination of the fair value of a share-based payment award using an option-pricing model requires the input of significant assumptions, such as the expected life of the award and stock price volatility.
Under the provisions of this FASB topic, we recognize expense, net of an estimated forfeiture rate, for all share-based awards granted on a straight-line basis over the requisite service periods of the awards, which is generally equivalent to the vesting term. This topic requires compensation expense to be recognized, net of an estimate for forfeitures, such that compensation expense is recorded only for those awards expected to vest. We review the estimate for forfeitures periodically and record any adjustments deemed necessary for each reporting period. If our actual forfeiture rate is materially different from our estimate, the stock-based compensation expense could be significantly different from what we have recorded in the current period.
Additionally, this FASB topic amended FASB Topic Statement of Cash Flows, to require excess tax benefits to be reported as a financing cash flow, rather than as a reduction of taxes paid. These excess tax benefits result from tax deductions in excess of the cumulative compensation expense recognized for options exercised and other equity-classified awards.
See Note 9 for a further discussion of stock-based compensation.
Recently Adopted Accounting Standards
In February 2013, the FASB issued an update to the Topic Liabilities. This update requires an entity to recognize obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. On January 1, 2014, we adopted this update. The adoption of these provisions did not have an impact on our financial statements.
In July 2013, the FASB issued an update to the Topic Income Taxes. This update relates to the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, similar tax loss, or tax credit carryforward exists. On January 1, 2014, we adopted this update. The adoption of these provisions did not have an impact on our financial statements.
In April 2014, the FASB issued an update to the Topics Presentation of Financial Statements and Property, Plant and Equipment. This update changes the criteria for reporting discontinued operations such that a disposal of a component of an entity will be required to be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results. We early adopted this pronouncement in the second quarter of 2014. The disposal of our Nuclear Projects business in the second quarter of 2014 did not qualify as a discontinued operation under the new guidance due to its relative insignificance to B&W’s operations and financial results. See Note 2 for additional information related to this disposal.
New Accounting Standards
In May 2014, the FASB issued Revenue from Contracts with Customers, which supersedes the revenue recognition requirements in the Topic Revenue Recognition and most industry specific guidance. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. This update is effective in 2017 and early adoption is not permitted. The update may be adopted either retrospectively to each prior period or as a cumulative-effect adjustment on the date of adoption. We are currently evaluating the impact of the adoption of this standard on our financial statements.
In August 2014, the FASB issued an update to the Topic Presentation of Financial Statements. This update requires an entity to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. If there is substantial doubt about an entity’s ability to continue as a going concern, certain disclosures are required. This update will be effective for us in 2017. We do not expect the adoption of this update to have a material impact on our financial statements.

Business_Acquisitions_and_Disp

Business Acquisitions and Dispositions	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Acquisitions and Dispositions	NOTE 2 – BUSINESS ACQUISITIONS AND DISPOSITIONS
	MEGTEC Acquisition
	On June 20, 2014, we acquired the outstanding stock of industrial processes solutions provider MEGTEC for $142.8 million, net of cash acquired. MEGTEC designs, engineers, manufactures and services air pollution control systems and coating/drying equipment for a variety of industrial applications and complements our Power Generation segment’s environmental products and solutions offerings that serves utility markets.
	The purchase price of the acquisition has been allocated among assets acquired and liabilities assumed at preliminary estimates of fair value based on information currently available with the excess purchase price recorded as goodwill. Our preliminary purchase price allocation, as follows, is subject to change upon receipt of additional information and completion of further analysis, including, but not limited to, finalization of long-lived and intangible asset valuations:
			MEGTEC
			(in thousands)
	Cash and cash equivalents		$	14,232
	Accounts receivable			23,054
	Inventories			5,395
	Other current assets			9,200
	Property, plant and equipment			5,090
	Goodwill			108,800
	Intangible assets			44,250
	Total assets acquired		$	210,021
	Accounts payable			13,402
	Advance billings on contracts			11,144
	Other current liabilities			18,089
	Pension liability			5,041
	Deferred income taxes			5,202
	Other liabilities			130
	Total liabilities assumed		$	53,008
	Net assets acquired		$	157,013
	Cash and cash equivalents acquired			14,232
	Net assets acquired, net of unrestricted cash acquired		$	142,781
	Amount of tax deductible goodwill		$	34,583
	The preliminary intangible assets included above consist of the following (dollar amounts in thousands):
			Amount		Amortization
					Period
	Customer relationships		$	24,400		7 years
	Backlog		$	10,600		1 year
	Trade names / trademarks		$	6,000		15 years
	Developed technology		$	3,250		10 years
	Our consolidated financial statements for the year ended December 31, 2014 includes $105.4 million of revenues and $3.3 million of net income related to MEGTEC operations occurring from the acquisition date to December 31, 2014. Additionally, the following unaudited pro forma financial information presents our results of operations for the years ended December 31, 2014 and 2013 had the acquisition of MEGTEC occurred on January 1, 2013. The unaudited pro forma financial information below is not intended to represent or be indicative of our actual consolidated results had we completed the acquisition at January 1, 2013. This information is presented for comparative purposes only and should not be taken as representative of our future consolidated results of operations.
			Year Ended
			December 31,
			2014		2013
	Revenues		$	3,003,351	$	3,445,597
	Net Income Attributable to The Babcock & Wilcox Company		$	36,357	$	341,774
	Basic Earnings per Common Share		$	0.34	$	3.05
	Diluted Earnings per Common Share		$	0.33	$	3.03
	The unaudited pro forma results include the following pre-tax adjustments to the historical results presented above:
		•		Increase (decrease) in amortization expense related to timing of amortization of the fair value of identifiable intangible assets acquired of approximately $(3.9) million and $12.6 million for the years ended December 31, 2014 and 2013, respectively.
		•		Elimination of historical interest expense of approximately $0.9 million and $2.4 million for the years ended December 31, 2014 and 2013, respectively.
		•		Additional interest expense associated with the incremental borrowings that would have been incurred to acquire MEGTEC as of January 1, 2013 of approximately $1.2 million and $2.5 million for the years ended December 31, 2014 and 2013, respectively.
		•		Elimination of $14.4 million in acquisition related costs recognized in the year ended December 31, 2014 that are not expected to be recurring.
	Ebensburg Acquisition
	On May 21, 2014, we acquired the remaining outstanding interest in Ebensburg Power Company for a purchase price of $1.3 million. As part of the transaction, we acquired cash of $16.4 million and property, plant and equipment with a fair value of $16.1 million.
	Nuclear Projects Business Disposition
	In the first quarter of 2014, we announced that we would exit our Nuclear Energy segment’s Nuclear Projects business as it had lower margins and higher financial risks. Run-off operations for remaining projects were completed during the quarter ended June 30, 2014. Income (loss) before provision for income taxes for the Nuclear Projects business was $(4.5) million and $(2.7) million in the years ended December 31, 2014 and 2013, respectively.
	At December 31, 2014, we had outstanding accounts receivable recorded within the consolidated financial statements for the Nuclear Projects business totaling $45.4 million. This amount relates to a reimbursable target cost subcontract pursuant to which we performed steam generator replacement installation services for the prime contractor at the Prairie Island Nuclear Generating Plant. See Note 10 for further discussion of this matter.

Equity_Method_Investments

Equity Method Investments	12 Months Ended
	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	NOTE 3 – EQUITY METHOD INVESTMENTS
	We have investments in entities that we account for using the equity method. The undistributed earnings of our equity method investees were $104.6 million and $113.0 million at December 31, 2014 and 2013, respectively.
	Summarized below is combined balance sheet and income statement information for investments accounted for under the equity method:
		December 31,
		2014			2013
		(In thousands)
	Current assets	$	706,845		$	800,704
	Noncurrent assets		181,517			252,430
	Total Assets	$	888,362		$	1,053,134
	Current liabilities	$	507,616		$	610,329
	Noncurrent liabilities		97,419			72,742
	Owners’ equity		283,327			370,063
	Total Liabilities and Owners’ Equity	$	888,362		$	1,053,134
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Revenues	$	2,109,159		$	2,832,202		$	2,758,159
	Gross profit	$	157,472		$	208,714		$	210,425
	Income before provision for income taxes	$	95,013		$	150,511		$	146,911
	Provision for income taxes		6,160			8,603			9,000
	Net Income	$	88,853		$	141,908		$	137,911
	Reimbursable costs recorded in revenues by the unconsolidated joint ventures in our Technical Services segment totaled $1,386.6 million, $2,121.0 million and $2,222.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. Our investment in equity method investees was $4.5 million more than our underlying equity in net assets of those investees based on stated ownership percentages at December 31, 2014. These differences were primarily related to the timing of distribution of dividends and various adjustments under GAAP.
	On January 8, 2013, we were notified that our joint venture, Nuclear Production Partners, LLC, was not selected to lead the NNSA’s combined Management and Operating contract for the Y-12 National Security Complex and Pantex Plant. Subsequently, we filed multiple protests with the Government Accountability Office in relation to the selection decision. On February 27, 2014, we received notification that our latest protest was dismissed. The transition of these facilities to the new contractor was completed on June 30, 2014, and is the primary cause of the decline in our equity method investments as of and for the period ended December 31, 2014.
	The provision for income taxes is based on the tax laws and rates in the countries in which our investees operate. The taxation regimes vary not only by their nominal rates, but also by the allowability of deductions, credits and other benefits. For some of our U.S. investees, U.S. income taxes are the responsibility of the respective owners, which is primarily the reason for the provision for income taxes being low in relation to income before provision for income taxes.
	Reconciliation of net income per combined income statement information of our investees to equity in income of investees per our consolidated statements of income is as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Equity income based on stated ownership percentages	$	43,263		$	68,305		$	66,064
	All other adjustments due to amortization of basis differences, timing of GAAP adjustments and other adjustments		(1,507	)		(247	)		645
	Equity in income of investees	$	41,756		$	68,058		$	66,709
	Our transactions with unconsolidated affiliates were as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Sales to	$	87,722		$	99,443		$	42,538
	Purchases from	$	5,623		$	4,645		$	1,814
	Dividends received	$	60,519		$	79,595		$	51,594
	Capital contributions, net of returns	$	4,900		$	6,884		$	6,289
	We recognized a $1.2 million gain in the year ended December 31, 2012 from the sale of our interest in a joint venture associated with the management and operations of the Strategic Petroleum Reserve.

Special_Charges_for_Restructur

Special Charges for Restructuring Activities	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Special Charges for Restructuring Activities	NOTE 4 – SPECIAL CHARGES FOR RESTRUCTURING ACTIVITIES
	Global Competitiveness Initiative
	In the third quarter of 2012, we announced the Global Competitiveness Initiative (“GCI”) to enhance competitiveness, better position B&W for growth, and improve profitability. In conjunction with GCI, during the year ended December 31, 2014, we incurred $0.2 million of expenses related to employee termination benefits and $3.1 million of expenses related to facility consolidation. During the year ended December 31, 2013, we reduced our workforce and initiated other actions, resulting in $23.7 million of expenses related to employee termination benefits, $8.5 million of expenses related to consulting and GCI administrative costs, and $7.4 million of expenses related to facility consolidation.
	Other Restructuring Actions
	In the first quarter of 2014, we announced a margin improvement program in our Power Generation and Nuclear Energy segments. In the year ended December 31, 2014, we incurred $26.8 million of expenses related to this project, including $12.8 million of expenses related to employee termination benefits, $3.2 million of expenses related to consulting and administrative costs and $10.8 million of expenses related to facility consolidation.
	In the year ended December 31, 2014, we also incurred $10.6 million of expenses related to the restructuring of our mPower program, including $7.3 million of expenses related to employee termination benefits, $3.0 million of expenses related to consulting and administrative costs and $0.3 million of expenses related to facility consolidation.
	Additionally, we incurred expenses related to employee termination benefits totaling $0.4 million for the year ended December 31, 2014 related to restructuring of our Technical Services segment.
			Year Ended December 31,
			2014			2013
			(In thousands)
	Liability balance at the beginning of the period		$	10,054		$	—
	Special charges for restructuring activities(1)			30,298			36,150
	Payments			(30,321	)		(26,096	)
	Translation and other			-366			—
	Liability balance at the end of the period		$	9,665		$	10,054
	-1	Excludes non-cash charges of $10.8 million and $3.4 million for the years ended December 31, 2014 and 2013, respectively, which did not impact the restructuring liability.
	At December 31, 2014, unpaid restructuring charges totaled $8.8 million for employee termination benefits and $0.9 million related to consulting and administrative costs.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 5 – INCOME TAXES
	B&W and its subsidiaries are subject to U.S. federal income tax and income tax of multiple state and international jurisdictions. We provide for income taxes based on the tax laws and rates in the jurisdictions in which we conduct our operations. These jurisdictions may have regimes of taxation that vary with respect to nominal rates and with respect to the basis on which these rates are applied. This variation, along with the changes in our mix of income within these jurisdictions, can contribute to shifts in our effective tax rate from period to period.
	The results of the U.S. operations of McDermott International, Inc. (“MII”) and/or certain of its subsidiaries were reflected in our consolidated return for U.S. federal income tax purposes and/or certain consolidated, combined and unitary returns for state, local and foreign tax purposes through June 7, 2010. The Statute of Limitations is closed for 2009 and prior U.S. federal income tax return years.
	We are currently under audit by various state and international authorities. With few exceptions, we do not have any returns under examination for years prior to 2010.
	We apply the provisions of FASB Topic Income Taxes regarding the treatment of uncertain tax positions. A reconciliation of unrecognized tax benefits follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Balance at beginning of period	$	5,730		$	4,487		$	32,357
	Increases based on tax positions taken in the current year		868			732			980
	Increases based on tax positions taken in the prior years		3,536			1,546			65
	Decreases based on tax positions taken in the prior years		(260	)		(167	)		(3,114	)
	Decreases due to settlements with tax authorities		(350	)		—			(1,101	)
	Decreases due to lapse of applicable statute of limitation		—			(868	)		(24,700	)
	Balance at end of period	$	9,524		$	5,730		$	4,487
	Of the $9.5 million balance of unrecognized tax benefits at December 31, 2014, $7.3 million would reduce our effective tax rate if recognized.
	We recognize interest and penalties related to unrecognized tax benefits in our provision for income taxes. During the year ended December 31, 2014, we recorded an increase in our accruals of $0.5 million, resulting in recorded liabilities of approximately $0.9 million for the payment of tax-related interest and penalties. At December 31, 2013 and 2012, our recorded liabilities for the payment of tax-related interest and penalties totaled approximately $0.4 million and $0.3 million, respectively.
	We believe that, within the next 12 months, it is reasonably possible that our previously unrecognized tax benefits could decrease by $3.0 million.
	Deferred income taxes reflect the net tax effects of temporary differences between the financial and tax bases of assets and liabilities. Significant components of deferred tax assets and liabilities as of December 31, 2014 and 2013 were as follows:
		December 31,
		2014			2013
		(In thousands)
	Deferred tax assets:
	Pension liability	$	210,580		$	105,370
	Accrued warranty expense		16,116			18,003
	Accrued vacation pay		12,968			12,865
	Accrued liabilities for self-insurance (including postretirement health care benefits)		27,881			33,349
	Accrued liabilities for executive and employee incentive compensation		26,731			45,413
	Environmental and products liabilities		22,353			8,858
	Investments in joint ventures and affiliated companies		23,285			23,780
	Long-term contracts		13,885			37,684
	Net operating loss carryforward		13,931			12,539
	State tax net operating loss carryforward		19,417			21,252
	Foreign tax credit carryforward		2,959			320
	Other		24,362			7,135
	Total deferred tax assets		414,468			326,568
	Valuation allowance for deferred tax assets		(22,196	)		(24,872	)
	Deferred tax assets		392,272			301,696
	Deferred tax liabilities:
	Property, plant and equipment		20,004			35,797
	Long-term contracts		27,707			27,628
	Intangibles		32,220			29,388
	Other		9,716			8,631
	Total deferred tax liabilities		89,647			101,444
	Net deferred tax assets	$	302,625		$	200,252
	Income before provision for income taxes was as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	U.S.	$	(4,705	)	$	399,263		$	222,840
	Other than U.S.		10,171			117,910			96,578
	Income before provision for income taxes	$	5,466		$	517,173		$	319,418
	The provision for income taxes consisted of:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Current:
	U.S. – federal	$	67,010		$	70,660		$	39,784
	U.S. – state and local		5,955			6,388			7,979
	Other than U.S.		6,741			13,467			11,060
	Total current		79,706			90,515			58,823
	Deferred:
	U.S. – Federal		(86,022	)		69,810			24,560
	U.S. – State and local		(3,945	)		6,546			6,545
Other than U.S.		(5,730	)		17,712			11,933
Total deferred (benefit) provision		(95,697	)		94,068			43,038
Provision for income taxes	$	(15,991	)	$	184,583		$	101,861
The following is a reconciliation of the U.S. statutory federal tax rate (35%) to the consolidated effective tax rate:
	Year Ended December 31,
	2014			2013			2012
U.S. federal statutory (benefit) rate		35	%		35	%		35	%
State and local income taxes		(10.1	)		2.5			4.3
Foreign rate differential		(72.5	)		(2.5	)		(4.1	)
Foreign operations		19.5			—			0.5
Tax credits		(75.0	)		(2.0	)		(2.5	)
Dividends and deemed dividends from affiliates		(70.0	)		1.2			2.3
Valuation allowances		(49.0	)		0.9			3.4
Uncertain tax positions		25.2			0.3			(9.0	)
Non-deductible expenses		52.7			0.4			1.3
Manufacturing deduction		(169.9	)		(1.4	)		(1.3	)
Minority interest		28			1			1.1
Other		(6.5	)		0.3			0.9
Effective tax rate		(292.6	)%		35.7	%		31.9	%
At December 31, 2014, we had a valuation allowance of $22.2 million for deferred tax assets, which we expect cannot be realized through carrybacks, future reversals of existing taxable temporary differences and our estimate of future taxable income. We believe that our remaining deferred tax assets are more likely than not realizable through carrybacks, future reversals of existing taxable temporary differences and our estimate of future taxable income. Any changes to our estimated valuation allowance could be material to our consolidated financial statements.
The following is an analysis of our valuation allowance for deferred tax assets:
	Beginning			Charges To			Charged To			Ending
	Balance			Costs and			Other			Balance
				Expenses			Accounts
	(In thousands)
Year Ended December 31, 2014	$	(24,872	)		2,676			—		$	(22,196	)
Year Ended December 31, 2013	$	(19,979	)		(4,893	)		—		$	(24,872	)
Year Ended December 31, 2012	$	(9,354	)		(10,625	)		—		$	(19,979	)
We have foreign net operating loss benefits of $11.1 million available to offset future taxable income in foreign jurisdictions. Of the foreign net operating loss benefits, $0.9 million is scheduled to expire in 2017 to 2033. We have foreign tax credit carryovers of $2.9 million which will not expire until 2018. We have state net operating losses of $29.9 million available to offset future taxable income in various states. Our state net operating loss carryforwards begin to expire in the year 2015. We are carrying a valuation allowance of $18.7 million against the deferred tax asset related to the state loss carryforwards.
We would be subject to withholding taxes if we were to distribute earnings from certain foreign subsidiaries. For the year ended December 31, 2014, the undistributed earnings of these subsidiaries were $347.1 million. Unrecognized deferred income tax liabilities, including withholding taxes, of approximately $44.1 million would be payable upon distribution of these earnings. We have provided tax of $0.6 million on earnings we intend to remit. All other earnings are considered permanently reinvested.

LongTerm_Debt_and_Notes_Payabl

Long-Term Debt and Notes Payable	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt and Notes Payable	NOTE 6 – LONG-TERM DEBT AND NOTES PAYABLE
		December 31,
		2014			2013
		(In thousands)
	Long-term debt consists of:
	Secured Debt:
	Credit Facility	$	300,000		$	—
	Power Generation – various notes payable		—			444
	Other		—			3
			300,000			447
	Less: Amounts due within one year		15,000			222
	Long-term debt	$	285,000		$	225
	Notes payable and current maturities of long-term debt consist of:
	Short-term lines of credit	$	3,215		$	4,449
	Current maturities of long-term debt		15,000			222
	Total	$	18,215		$	4,671
	Weighted average interest rate on short term borrowings		2.6	%		6.6	%
	Our short-term lines of credit represent borrowings by one of our subsidiaries. We have included this amount in notes payable and current maturities of long-term debt on our consolidated balance sheets. This facility is renewable annually and the interest rate associated with this line of credit was 6.3% per annum at December 31, 2014.
	Maturities of long-term debt during the five years subsequent to December 31, 2014 are as follows: 2015 – $18.2 million; 2016 – $15.0 million; 2017 – $15.0 million; 2018 – $15.0 million; and 2019 – $240.0 million.
	Credit Facility
	On June 24, 2014, B&W entered into a Second Amended and Restated Credit Agreement (the “New Credit Agreement”) with a syndicate of lenders and letter of credit issuers, and Bank of America, N.A., as administrative agent, which amends and restates our previous Credit Agreement dated June 8, 2012. The New Credit Agreement provides for revolving credit borrowings and issuances of letters of credit in an aggregate amount of up to $1.0 billion and a term loan facility of $300 million. The New Credit Agreement is scheduled to mature on June 24, 2019. The proceeds of the New Credit Agreement are available for the issuance of letters of credit, working capital needs and other general corporate purposes. The New Credit Agreement includes provisions that allow for additional financial institutions to become lenders, or for any existing lender to increase its commitment thereunder, subject to an aggregate maximum of $400 million for all incremental term loan, revolving credit borrowings and letter of credit commitments.
	The New Credit Agreement is guaranteed by substantially all of B&W’s wholly owned domestic subsidiaries. Obligations under the New Credit Agreement are secured by first-priority liens on certain assets owned by B&W and the guarantors (other than our subsidiaries comprising our Nuclear Operations and Technical Services segments). If the corporate family rating of B&W and its subsidiaries from Moody’s is Baa3 or better (with a stable outlook or better), the corporate rating of B&W and its subsidiaries from S&P is BBB- or better (with a stable outlook or better), and other conditions are met, the liens securing obligations under the New Credit Agreement will be released, subject to reinstatement upon the terms set forth in the New Credit Agreement. B&W’s current corporate family rating from Moody’s is Ba1 and its current corporate rating from S&P is BB+.
	The New Credit Agreement requires interest payments on revolving loans on a periodic basis until maturity. Beginning with the first quarter of 2015, we are also required to make quarterly amortization payments on the term loan portion of the New Credit Agreement in an amount equal to 1.25% of the aggregate principal amount of the term loan facility. We may prepay all loans under the New Credit Agreement at any time without premium or penalty (other than customary LIBOR breakage costs), subject to notice requirements. We are also required to make certain prepayments on any outstanding term loans under the New Credit Agreement after receipt of cash proceeds from certain asset sales or other events, subject to certain exceptions and our right to reinvest such proceeds in certain circumstances, all as more particularly set forth in the New Credit Agreement.
	The New Credit Agreement contains financial covenants relating to leverage and interest coverage and includes covenants that restrict, among other things, debt incurrence, liens, investments, acquisitions, asset dispositions, dividends, prepayments of subordinated debt and mergers. At December 31, 2014, we were in compliance with all covenants set forth in the New Credit Agreement.
	Loans outstanding under the New Credit Agreement bear interest at our option at either the Eurocurrency rate plus a margin ranging from 1.25% to 2.00% per year or the base rate (the highest of the Federal Funds rate plus 0.50%, the one month Eurocurrency rate plus 1.00%, or the administrative agent’s prime rate) plus a margin ranging from 0.25% to 1.00% per year. The applicable margin for loans varies depending on the credit ratings of the New Credit Agreement. Under the New Credit Agreement, we are charged a commitment fee on the unused portions of the New Credit Agreement, and that fee varies between 0.200% and 0.350% per year depending on the credit ratings of the New Credit Agreement. Additionally, we are charged a letter of credit fee of between 1.250% and 2.000% per year with respect to the amount of each financial letter of credit issued under the New Credit Agreement and a letter of credit fee of between 0.725% and 1.125% per year with respect to the amount of each performance letter of credit issued under the New Credit Agreement, in each case depending on the credit ratings of the New Credit Agreement. We also pay customary fronting fees and other fees and expenses in connection with the issuance of letters of credit under the New Credit Agreement. In connection with entering into the New Credit Agreement, we paid upfront fees to the lenders thereunder, and arrangement and other fees to the arrangers and agents of the New Credit Agreement. At December 31, 2014, borrowings outstanding totaled $300.0 million under our term loan. Letters of credit issued under the New Credit Agreement totaled $171.9 million, resulting in $828.1 million available for borrowings or to meet letter of credit requirements.
	Based on the current credit ratings of the New Credit Agreement, the applicable margin for Eurocurrency rate loans is 1.375%, the applicable margin for base rate loans is 0.375%, the letter of credit fee for financial letters of credit is 1.375%, the letter of credit fee for performance letters of credit is 0.80%, and the commitment fee for unused portions of the New Credit Agreement is 0.225%. The New Credit Agreement does not have a floor for the base rate or the Eurocurrency rate. As of December 31, 2014, the interest rate on our term loan borrowings was 1.54%.
	The New Credit Agreement generally includes customary events of default for a secured credit facility. If any default occurs under the New Credit Agreement, or if we are unable to make any of the representations and warranties in the New Credit Agreement, we will be unable to borrow funds or have letters of credit issued under the New Credit Agreement.
	Other Arrangements
	Certain subsidiaries within our Power Generation segment have credit arrangements with various commercial banks and other financial institutions for the issuance of letters of credit and bank guarantees in association with contracting activity. The aggregate value of all such letters of credit and bank guarantees as of December 31, 2014 was $101.5 million.
	We have posted surety bonds to support contractual obligations to customers relating to certain projects. We utilize bonding facilities to support such obligations, but the issuance of bonds under those facilities is typically at the surety’s discretion. Although there can be no assurance that we will maintain our surety bonding capacity, we believe our current capacity is adequate to support our existing project requirements for the next twelve months. In addition, these bonds generally indemnify customers should we fail to perform our obligations under the applicable contracts. We, and certain of our subsidiaries, have jointly executed general agreements of indemnity in favor of surety underwriters relating to surety bonds those underwriters issue in support of some of our contracting activity. As of December 31, 2014, bonds issued and outstanding under these arrangements in support of contracts totaled approximately $437.9 million.

Pension_Plans_and_Postretireme

Pension Plans and Postretirement Benefits	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Pension Plans and Postretirement Benefits	NOTE 7 – PENSION PLANS AND POSTRETIREMENT BENEFITS
	We have historically provided defined benefit retirement benefits, primarily through noncontributory pension plans, for most of our regular employees. As of 2006, our retirement plans for U.S.-based employees were closed to new entrants for our corporate employees and were closed to new salaried plan entrants for our existing plans within our Power Generation and Nuclear Operations segments.
	In October 2012, we notified employees that, effective December 31, 2015, benefit accruals for those salaried employees covered by, and continuing to accrue service and salary adjusted benefits under our major U.S. and Canadian defined benefit qualified pension plans will cease. Furthermore, effective January 1, 2016, we will make service-based, cash contributions to The Babcock & Wilcox Company Thrift Plan (the “Thrift Plan”) for those employees impacted by the plan freeze.
	Effective January 1, 2012, a defined contribution component was adopted applicable to Babcock & Wilcox Canada, Ltd. (the “Canadian Plans”). Any employee with less than two years of continuous service as of December 31, 2011 was required to enroll in the defined contribution component of the Canadian Plans as of January 1, 2012 or upon the completion of six months of continuous service, whichever is later. These and future employees will not be eligible to enroll in the defined benefit component of the Canadian Plans. Additionally, during the third quarter of 2014, benefit accruals under certain hourly Canadian pension plans were ceased with an effective date of January 1, 2015. This amendment to the Canadian Plans is reflected as a curtailment in 2014.
	We do not provide retirement benefits to certain non-resident alien employees of foreign subsidiaries. Retirement benefits for salaried employees who accrue benefits in a defined benefit plan are based on final average compensation and years of service, while benefits for hourly paid employees are based on a flat benefit rate and years of service. Our funding policy is to fund the plans as recommended by the respective plan actuaries and in accordance with the Employee Retirement Income Security Act of 1974, as amended, or other applicable law. The Pension Protection Act of 2006 became effective in 2008. Funding provisions under the Pension Protection Act accelerate funding requirements to ensure full funding of benefits accrued. Assuming we continue as a government contractor, our contractual arrangements with the U.S. Government provide for the recovery of contributions to our pension and other postretirement benefit plans covering employees working primarily in our Nuclear Operations segment.
	We make available other benefits which include postretirement health care and life insurance benefits to certain salaried and union retirees based on their union contracts. Certain subsidiaries provide these benefits to unionized and salaried future retirees.
	Obligations and Funded Status
			Pension Benefits						Other Benefits Year
			Year Ended						Ended December 31,
			December 31,
			2014			2013			2014				2013
			(In thousands)
	Change in benefit obligation:
	Benefit obligation at beginning of period		$	2,570,095		$	2,779,990		$	95,906			$	116,256
	Service cost			37,878			46,417			777				975
	Interest cost			119,368			111,200			3,827				3,745
	Plan participants’ contributions			264			266			1,546				1,055
	Curtailments			772			—			—				—
	Amendments			305			3,105			—				—
	Acquisition			5,108			—			—				—
	Settlements			(23,339	)		(21,862	)		—				—
	Actuarial loss (gain)			366,146			(195,290	)		12,974				(16,335	)
	Foreign currency exchange rate changes			(20,709	)		(17,465	)		(691	)			(655	)
	Benefits paid			(146,900	)		(136,266	)		(7,902	)			(9,135	)
	Benefit obligation at end of period		$	2,908,988		$	2,570,095		$	106,437			$	95,906
	Change in plan assets:
	Fair value of plan assets at beginning of period		$	2,181,323		$	2,127,694		$	43,274			$	37,324
	Actual return on plan assets			288,630			155,071			(415	)			6,056
	Plan participants’ contributions			264			266			1,546				1,055
	Company contributions			63,649			70,681			5,248				7,974
	Settlements			(23,339	)		(21,862	)		—				—
	Foreign currency exchange rate changes			(19,183	)		(14,261	)		—				—
	Benefits paid			(146,900	)		(136,266	)		(7,902	)			(9,135	)
	Fair value of plan assets at the end of period			2,344,444			2,181,323			41,751				43,274
	Funded status		$	(564,544	)	$	(388,772	)	$	(64,686	)		$	(52,632	)
	Amounts recognized in the balance sheet consist of:
	Accrued employee benefits		$	(4,051	)	$	(54,391	)	$	(6,473	)		$	(9,438	)
	Accumulated postretirement benefit obligation			—			—			(58,213	)			(43,194	)
	Pension liability			(562,176	)		(334,538	)		—				—
	Prepaid pension			1,683			157			—				—
	Accrued benefit liability, net		$	(564,544	)	$	(388,772	)	$	(64,686	)		$	(52,632	)
	Amount recognized in accumulated comprehensive income (before taxes):
	Prior service cost (credit)		$	14,204		$	18,237		$	(2,181	)		$	(2,338	)
	Supplemental information:
	Plans with accumulated benefit obligation in excess of plan assets
	Projected benefit obligation		$	2,789,053		$	2,433,369			N/A				N/A
	Accumulated benefit obligation		$	2,770,436		$	2,406,269		$	106,437			$	95,906
	Fair value of plan assets		$	2,222,825		$	2,047,507		$	41,751			$	43,274
	Plans with plan assets in excess of accumulated benefit obligation
	Projected benefit obligation		$	119,935		$	136,726			N/A				N/A
	Accumulated benefit obligation		$	117,503		$	132,221		$	—			$	—
	Fair value of plan assets		$	121,619		$	133,816		$	—			$	—
			Pension Benefits										Other Benefits Year Ended
			Year Ended										December 31,
			December 31,
			2014			2013			2012				2014				2013				2012
			(In thousands)
	Components of net periodic benefit cost:
	Service cost		$	37,878		$	46,417		$	46,828			$	777			$	975			$	1,138
	Interest cost			119,368			111,200			122,605				3,827				3,745				5,124
	Expected return on plan assets			(149,231	)		(147,621	)		(136,913	)			(2,295	)			(2,116	)			(1,930	)
	Amortization of prior service cost			2,672			3,158			3,579				(163	)			(148	)			(139	)
	Recognized net actuarial loss (gain)			229,053			(202,442	)		34,496				12,574				(20,483	)			(2,456	)
	Net periodic benefit cost (income)		$	239,740		$	(189,288	)	$	70,595			$	14,720			$	(18,027	)		$	1,737
Recognized net actuarial loss (gain) consists primarily of our reported actuarial loss (gain), curtailments, and the difference between the actual return on plan assets and the expected return on plan assets. Additionally, we adjusted our mortality assumption in the year ended December 31, 2014, resulting in a $117.7 million increase in our pension liability. As discussed in Note 16, we have excluded the recognized net actuarial loss (gain) from our reportable segments and such amount has been reflected in Note 16 as the Mark to Market Adjustment in the reconciliation of reportable segment income to consolidated operating income. The recognized net actuarial loss (gain) and the affected consolidated statements of income line items are as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
Cost of operations		$	223,269		$	(191,352	)	$	23,893
Selling, general and administrative expenses			17,887			(31,384	)		7,997
Other-net			471			(189	)		150
Total		$	241,627		$	(222,925	)	$	32,040
Additional Information
		Pension Benefits						Other Benefits
		Year Ended						Year Ended
		December 31,						December 31,
		2014			2013			2014				2013
		(In thousands)
Increase (decrease) in accumulated other comprehensive income due to actuarial losses - before taxes		$	(1,351	)	$	(3,105	)	$	—			$	—
In the current fiscal year, we have recognized expense (income) in other comprehensive income as a component of net periodic benefit cost of approximately $2.7 million and $(0.2) million for our pension benefits and other benefits, respectively. In the next fiscal year, we expect to recognize expense (income) in other comprehensive income as a component of net periodic benefit cost of approximately $2.2 million and $(0.2) million for our pension benefits and other benefits, respectively.
Assumptions
		Pension Benefits						Other Benefits
		2014			2013			2014				2013
Weighted average assumptions used to determine net periodic benefit obligations at December 31:
Discount rate			3.99	%		4.78	%		3.74	%			4.23	%
Rate of compensation increase			2.57	%		2.56	%		—				—
Weighted average assumptions used to determine net periodic benefit cost for the years ended December 31:
Discount rate			4.78	%		4.09	%		4.23	%			3.43	%
Expected return on plan assets			7	%		7.06	%		5.73	%			5.74	%
Rate of compensation increase			2.56	%		2.57	%		—				—
The expected rate of return on plan assets assumption is based on the long-term expected returns for the investment mix of assets currently in the portfolio. In setting this rate, we use a building-block approach. Historic real return trends for the various asset classes in the plan’s portfolio are combined with anticipated future market conditions to estimate the real rate of return for each class. These rates are then adjusted for anticipated future inflation to determine estimated nominal rates of return for each class. The expected rate of return on plan assets is determined to be the weighted average of the nominal returns based on the weightings of the classes within the total asset portfolio. We are using an expected return on plan assets assumption of 7.2% for the majority of our existing pension plan assets (approximately 90% of our total pension assets at December 31, 2014).
Our existing other benefit plans are unfunded, with the exception of the NFS postretirement benefit plans. These plans provide health benefits to certain salaried and hourly employees, as well as retired employees, of NFS. Approximately 87% of total assets for these postretirement benefit plans are contributed into a Voluntary Employees’ Beneficiary Association trust.
		2014			2013
Assumed health care cost trend rates at December 31
Health care cost trend rate assumed for next year			7.5	%		8	%
Rates to which the cost trend rate is assumed to decline (ultimate trend rate)			4.5	%		4.5	%
Year that the rate reaches ultimate trend rate			2021			2021
Assumed health care cost trend rates have a significant effect on the amounts we report for our health care plan. A one-percentage-point change in our assumed health care cost trend rates would have the following effects:
		One-Percentage-			One-Percentage-
		Point Increase			Point Decrease
		(In thousands)
Effect on total of service and interest cost		$	425		$	(331	)
Effect on postretirement benefit obligation		$	8,802		$	(7,400	)
Investment Goals
General
The overall investment strategy of the pension trusts is to achieve long-term growth of principal, while avoiding excessive risk and to minimize the probability of loss of principal over the long term. The specific investment goals that have been set for the pension trusts in the aggregate are (1) to ensure that plan liabilities are met when due and (2) to achieve an investment return on trust assets consistent with a reasonable level of risk.
Allocations to each asset class for both domestic and foreign plans are reviewed periodically and rebalanced, if appropriate, to assure the continued relevance of the goals, objectives and strategies. The pension trusts for both our domestic and foreign plans employ a professional investment advisor and a number of professional investment managers whose individual benchmarks are, in the aggregate, consistent with the plan’s overall investment objectives. The goals of each investment manager are (1) to meet (in the case of passive accounts) or exceed (for actively managed accounts) the benchmark selected and agreed upon by the manager and the pension trust and (2) to display an overall level of risk in its portfolio that is consistent with the risk associated with the agreed upon benchmark.
The investment performance of total portfolios, as well as asset class components, is periodically measured against commonly accepted benchmarks, including the individual investment manager benchmarks. In evaluating investment manager performance, consideration is also given to personnel, strategy, research capabilities, organizational and business matters, adherence to discipline and other qualitative factors that may impact the ability to achieve desired investment results.
Domestic Plans
We sponsor the following domestic defined benefit plans:
	•		Retirement Plan for Employees of Babcock & Wilcox Commercial Operations (covering Power Generation and Nuclear Energy segment employees);
	•		Retirement Plan for Employees of Babcock & Wilcox Governmental Operations (covering Nuclear Operations and Technical Services segment employees and Corporate employees);
	•		Nuclear Fuel Services, Inc. Retirement Plan for Salaried Employees; and
	•		Nuclear Fuel Services, Inc. Retirement Plan for Hourly Employees.
The assets of the domestic pension plans are commingled for investment purposes and held by the trustee in The Babcock & Wilcox Company Master Trust (the “Master Trust”). For the years ended December 31, 2014 and 2013, the investment return on domestic plan assets of the Master Trust (net of deductions for management fees) was approximately 14% and 7%, respectively.
The following is a summary of the asset allocations for the Master Trust at December 31, 2014 and 2013 by asset category:
		2014			2013
Asset Category:
Fixed Income (excluding U. S. Government Securities)			38	%		30	%
Commingled and Mutual Funds			33	%		36	%
U.S. Government Securities			15	%		18	%
Equity Securities			7	%		7	%
Partnerships with Security Holdings			5	%		6	%
Real Estate			1	%		1	%
Other			1	%		2	%
Total			100	%		100	%
The target allocation for 2015 for the domestic plans, by asset class, is as follows:
Asset Class:
Fixed Income			55	%
Equities			45	%
Foreign Plans
We sponsor various plans through certain of our foreign subsidiaries. These plans are the Canadian Plans and the Diamond Power Specialty Limited Retirement Benefits Plan (the “Diamond UK Plan”).
The combined weighted average asset allocations of these plans at December 31, 2014 and 2013 by asset category were as follows:
		2014			2013
Asset Category:
Equity Securities and Commingled Mutual Funds			55	%		58	%
Fixed Income			43	%		39	%
Other			2	%		3	%
Total			100	%		100	%
The target allocation for 2015 for the foreign plans, by asset class, is as follows:
		Canadian			Diamond
		Plans			UK Plan
Asset Class:
U. S. Equity			17	%		12	%
Global Equity			38	%		15	%
Fixed Income			45	%		73	%
Fair Value
See Note 15 for a detailed description of fair value measurements and the hierarchy established for valuation inputs. The following is a summary of total investments for our plans measured at fair value at December 31, 2014:
		12/31/14			Level 1			Level 2				Level 3
		(In thousands)
Pension and Other Benefits:
Fixed Income		$	907,046		$	—		$	907,046			$	—
Equities			141,471			141,471			—				—
Commingled and Mutual Funds			839,472			24,852			814,620				—
U.S. Government Securities			324,169			308,867			15,302				—
Partnerships with Security Holdings			110,565			—			—				110,565
Real Estate			4,831			—			—				4,831
Cash and Accrued Items			58,641			51,700			6,941				—
Total Assets		$	2,386,195		$	526,890		$	1,743,909			$	115,396
The following is a summary of total investments for our plans measured at fair value at December 31, 2013:
		12/31/13			Level 1			Level 2				Level 3
		(In thousands)
Pension and Other Benefits:
Fixed Income		$	682,028		$	—		$	682,028			$	—
Equities			144,438			144,438			—				—
Commingled and Mutual Funds			861,354			31,083			830,271				—
U.S. Government Securities			355,245			355,245			—				—
Partnerships with Security Holdings			116,154			—			—				116,154
Real Estate			6,214			—			—				6,214
Cash and Accrued Items			59,164			48,087			11,077				—
Total Assets		$	2,224,597		$	578,853		$	1,523,376			$	122,368
The following is a summary of the changes in the Plans’ Level 3 instruments measured on a recurring basis for the years ended December 31, 2014 and 2013:
		Year ended December 31,
		2014			2013
		(In thousands)
Balance at beginning of period		$	122,368		$	127,400
Issuances and acquisitions			10,387			6,016
Dispositions			(34,471	)		(31,471	)
Realized gain			24,835			18,058
Unrealized gain			(7,723	)		2,365
Balance at end of period		$	115,396		$	122,368
Our Level 3 instruments include assets with no market price but rather calculations of net asset values per share or its equivalent. When appropriate, we adjust these net asset values for contributions and distributions, if any, made during the period beginning on the latest net asset value valuation date and ending on our measurement date. We also consider available market data, relevant index returns, preliminary estimates from our investees and other data obtained through research and consultation with third party advisors in determining the fair value of our Level 3 instruments.
Cash Flows
		Domestic Plans						Foreign Plans
		Pension			Other			Pension				Other
		Benefits			Benefits			Benefits				Benefits
		(In thousands)
Expected employer contributions to trusts of defined benefit plans:
2015		$	330		$	2,271		$	14,618				N/A
Expected benefit payments:
2015		$	140,258		$	8,245		$	10,538			$	513
2016			145,703			7,832			10,832				501
2017			150,335			7,428			11,144				519
2018			154,417			7,258			11,536				544
2019			157,714			7,233			11,909				545
2020-2024			813,034			32,172			64,854				2,873
Defined Contribution Plans
We provide benefits under The Babcock & Wilcox Company Supplemental Executive Retirement Plan (the “SERP Plan”), which is a defined contribution plan. We recorded expense related to the SERP Plan of approximately $0.5 million, $0.7 million and $0.6 million in the years ended December 31, 2014, 2013 and 2012, respectively.
We also provide benefits under the Thrift Plan. The Thrift Plan generally provides for matching employer contributions of 50% of participants’ contributions up to 6% of compensation. These matching employer contributions are typically made in shares of B&W common stock. We also provide service-based cash contributions under the Thrift Plan to employees not accruing benefits under our defined benefit plans. Amounts charged to expense for employer contributions under the Thrift Plan totaled approximately $25.5 million, $24.3 million and $24.2 million in the years ended December 31, 2014, 2013 and 2012, respectively.
Effective January 1, 2012, we adopted The Babcock & Wilcox Company Defined Contribution Restoration Plan (the “Restoration Plan”) to restore benefits that would be provided to participants in the Thrift Plan but are precluded by the application of certain sections of the Internal Revenue Code of 1986, as amended (the “Code”). Each participant who is precluded from receiving the full amount of service-based contributions otherwise provided under the Thrift Plan in a plan year by the application of Code Section 401(a)(17) or 415(c) shall be credited with an employer service-based contribution for such plan year equal to the excess of the amount of service-based contributions that would have been made to the participant’s Thrift Plan account without the application of Code Section 401(a)(17) and 415(c) for the plan year over the amount of service-based contribution actually made to such participant’s Thrift Plan account for the plan year. In addition, the Restoration Plan permits participants who are precluded from making the full amount of employee contributions to the Thrift Plan and receiving associated employer matching contributions by the application of Code Sections 401(a)(17) and 415(c) to elect to make deferral contributions and receive associated employer matching contributions under the Restoration Plan. Amounts charged to expense under the Restoration Plan totaled approximately $0.2 million, $0.2 million and $0.1 million in the years ended December 31, 2014, 2013 and 2012, respectively.
Effective January 1, 2012, a defined contribution component was added to those Canadian Plans previously offering defined benefits to salaried employees. As of January 1, 2012, we made cash, service-based contributions under this arrangement. The amount charged to expense for employer contributions was approximately $0.6 million, $0.6 million and $0.5 million in the years ended December 31, 2014, 2013 and 2012, respectively.
Multiemployer Plans
One of our subsidiaries in the Power Generation segment contributes to various multiemployer plans. The plans generally provide defined benefits to substantially all unionized workers in this subsidiary.
The following table summarizes our contributions to multiemployer plans for the years covered by this report:
Pension Fund		EIN/PIN			Pension Protection			FIP/RP  Status		Contributions														Expiration Date
					Act Zone			Pending/																Of Collective
					Zone Status			Implemented		2014				2013				2012				Surcharge		Bargaining
					2014		2013			(in millions)												Imposed		Agreement
Boilermaker-Blacksmith National Pension Trust			48-6168020/		Yellow		Yellow	Yes		$	16			$	19			$	18.9				No	Described
			1																					Below
All Other											4.6				11.9				5.3
										$	20.6			$	30.9			$	24.2
The Boilermaker-Blacksmith National Pension Trust (the “Boilermaker Plan”) is, by plan, the only significant contribution of our total contributions to these funds. Our collective bargaining agreements with the Boilermaker Plan are under a National Maintenance Agreement platform which is evergreen in terms of expiration. However, the agreement allows for termination by either party with a 90-day written notice. Our contributions to the Boilermaker Plan constitute less than 5% of total contributions to the plan. All other contributions expense for all periods included in this report represents multiple amounts to various plans that, individually, are deemed to be insignificant.

Capital_Stock

Capital Stock	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Capital Stock	NOTE 8 – CAPITAL STOCK
	In November 2012, our Board of Directors authorized us to repurchase an indeterminate number of shares of our common stock at an aggregate value of up to $250 million. In addition, in May 2013 our Board of Directors authorized us to repurchase an additional $250 million of aggregate value of common stock. On February 26, 2014, we announced that our Board of Directors authorized us to repurchase an indeterminate number of shares of our common stock at an aggregate market value of up to $250 million. The May 2013 and February 2014 authorizations are in addition to the initial $250 million share repurchase amount authorized in November 2012. On December 9, 2013, we completed the repurchase of shares using our initial $250 million authorization. We may repurchase shares in the open market using the additional repurchase amounts authorized in May 2013 and February 2014 during a two-year period that expires February 25, 2016.
	In the year ended December 31, 2014, we repurchased 4,687,500 shares of common stock for approximately $149.7 million. In the year ended December 31, 2013, we repurchased 5,620,690 shares of common stock for approximately $157.0 million, and in the year ended December 31, 2012, we repurchased 3,908,684 shares of common stock for approximately $96.7 million.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	NOTE 9 – STOCK-BASED COMPENSATION
	2010 Long-Term Incentive Plan of The Babcock & Wilcox Company
	We established the 2010 Long-Term Incentive Plan of The Babcock & Wilcox Company (the “Plan”) allowing members of the Board of Directors, executive officers, key employees and consultants eligibility to participate in the Plan. The Compensation Committee of the Board of Directors selects the participants for the Plan. The Plan provides for a number of forms of stock-based compensation, including incentive and non-qualified stock options, restricted stock, restricted stock units, performance shares and performance units, subject to satisfaction of specific performance goals. Shares subject to awards under the Plan that are cancelled, forfeited, terminated or expire unexercised, shall immediately become available for the granting of awards under this Plan. As part of the approval of the Plan, 10,000,000 shares of common stock were initially authorized for issuance through the Plan, with an additional 2,300,000 authorized for issuance during the year ended December 31, 2014. Options to purchase shares are granted at not less than 100% of the fair market value closing price on the date of grant, become exercisable at such time or times as determined when granted and expire not more than seven years after the date of grant.
	At December 31, 2014, we had awarded 7,179,441 shares under the Plan and had a total of 5,120,559 shares of our common stock available for future awards. In the event of a change in control of our company, the terms of the awards under the Plan contain provisions that may cause restrictions to lapse and accelerate the vesting of plan awards.
	2012 Long-Term Incentive Plan of Babcock & Wilcox Technical Services Group, Inc.
	In June 2012, we established the 2012 Long-Term Incentive Plan of Babcock & Wilcox Technical Services Group, Inc., a cash-settled plan for employees of certain subsidiaries and unconsolidated affiliates as selected by the plan committee. The cash-settled plan provides for a number of forms of stock-based compensation, including stock appreciation rights, restricted stock units and performance units, subject to satisfaction of specific performance goals. Stock appreciation rights are granted at not less than 100% of the fair market value closing price of a share of B&W common stock on the date of grant, become exercisable at such time or times as determined when granted and expire not more than seven years after the date of grant. Stock appreciation rights are cash settled for the excess of the market price of B&W common stock on the exercise date minus the exercise price. Restricted stock units and performance units are cash settled upon vesting as determined when granted. We will not issue any shares of B&W common stock under this plan, as all awards are cash settled.
	In the event of a change in control of our company, the terms of the awards under the cash-settled plan contain provisions that may cause restrictions to lapse and accelerate the vesting of plan awards.
	Total stock-based compensation expense for all of our plans recognized for the years ended December 31, 2014, 2013 and 2012 totaled $9.8 million, $16.5 million and $18.3 million, respectively, with associated tax benefit recognized for the years ended December 31, 2014, 2013 and 2012 totaling $3.2 million, $6.2 million and $6.9 million, respectively.
	As of December 31, 2014, unrecognized estimated compensation expense related to nonvested awards was $24.5 million, which is expected to be recognized over a weighted-average period of 1.9 years.
	B&W Stock Options
	The fair value of each option grant was estimated at the date of grant using Black-Scholes, with the following weighted-average assumptions:
		Year Ended
		December 31,
		2014			2013			2012
	Risk-free interest rate		0.97	%		0.56	%		0.65	%
	Expected volatility		0.3			0.33			0.36
	Expected life of the option in years		3.76			3.93			3.98
	Expected dividend yield		1.22	%		1.19	%		0	%
	The risk-free interest rate is based on the implied yield on a U.S. Treasury zero-coupon issue with a remaining term equal to the expected life of the option. The expected volatility is based on implied volatility from publicly traded options on our common stock, historical volatility of the price of our common stock and other factors. The expected life of the option is based on observed historical patterns. The expected dividend yield is based on the projected annual dividend payment per share divided by the stock price at the date of grant. This amount was zero prior to 2013 because we did not expect to pay dividends at the grant dates for those stock options awarded.
	The following table summarizes activity for our stock options for the year ended December 31, 2014 (share data in thousands):
		Number			Weighted-			Weighted-			Aggregate
		of			Average			Average			Intrinsic
		Shares			Exercise			Remaining			Value
					Price			Contractual			(in  millions)
								Term
	Outstanding at beginning of period		1,974		$	26.87
	Granted		943			32.66
	Exercised		(194	)		21.5
	Cancelled/expired/forfeited		(176	)		30.88
	Outstanding at end of period		2,547		$	29.15			4.9 Years		$	6.3
	Exercisable at end of period		989		$	27.76			3.7 Years		$	3.8
	The aggregate intrinsic value included in the table above represents the total pretax intrinsic value that would have been received by the option holders had all option holders exercised their options on December 31, 2014. The intrinsic value is calculated as the total number of option shares multiplied by the difference between the closing price of our common stock on the last trading day of the period and the exercise price of the options. This amount changes based on the price of our common stock.
	The weighted-average fair value of the stock options granted in the years ended December 31, 2014, 2013 and 2012 was $7.03, $6.41 and $7.30, respectively.
	During the years ended December 31, 2014, 2013 and 2012, the total intrinsic value of stock options exercised was $2.1 million, $2.3 million and $3.8 million, respectively. The actual tax benefits realized related to the stock options exercised during the year ended December 31, 2014 were $0.8 million.
	B&W Performance Shares
	Nonvested performance shares as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (share data in thousands):
		Number			Weighted-
		of			Average
		Shares			Grant Date
					Fair Value
	Nonvested at beginning of period		834		$	29.07
	Adjustment to assumed vesting percentage		(294	)		27.38
	Granted		365			32.79
	Vested		(270	)		32.77
	Cancelled/forfeited		(100	)		29.38
	Nonvested at end of period		535		$	30.64
	For performance shares granted prior to 2014, the actual number of shares in which each participant vests is dependent upon achievement of certain Return on Invested Capital and Diluted Earnings Per Share targets over three-year performance periods. With respect to performance shares granted during 2014, the actual number of shares in which each participant vests is dependent upon those same targets as well as an additional Relative Total Shareholder Return target comparing B&W stock price performance to that of a custom peer group, over a three-year performance period. The number of shares in which participants can vest ranges from zero to 200% of the initial performance shares granted, to be determined upon completion of the three-year performance period. The nonvested shares at the end of the period in the table above assumes weighted-average vesting of 56%.
	The actual tax benefits realized related to the performance shares vested during the year ended December 31, 2014 were $3.3 million.
	B&W Restricted Stock Units
	Nonvested restricted stock units as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (share data in thousands):
		Number			Weighted-
		of			Average
		Shares			Grant Date
					Fair Value
	Nonvested at beginning of period		385		$	26.78
	Granted		225			32.84
	Vested		(206	)		28.43
	Cancelled/forfeited		(28	)		29.02
	Nonvested at end of period		376		$	29.33
	The actual tax benefits realized related to the restricted stock units vested during the year ended December 31, 2014 were $2.3 million.
	Cash-Settled Stock Appreciation Rights
	The fair value of each stock appreciation right grant was calculated at the grant date using Black-Scholes and was remeasured at the end of the reporting period with the following weighted-average assumptions:
		Year Ended
		December 31,
	2014			2013			2012
Risk-free interest rate		1.12	%		0.77	%		0.5	%
Expected volatility		0.25			0.3			0.32
Expected life of the option in years		3.21			3.21			3.55
Expected dividend yield		1.42	%		1.19	%		1.23	%
The risk-free interest rate is based on the implied yield on a U.S. Treasury zero-coupon issue with a remaining term equal to the expected life of the stock appreciation right. The expected volatility is based on implied volatility from publicly traded options on our common stock, historical volatility of the price of our common stock and other factors. The expected life of the stock appreciation right is based on observed historical patterns and the length of time each award has been outstanding as of each measurement date. The expected dividend yield is based on the projected annual dividend payment per share divided by the stock price at the date of measurement.
The following table summarizes activity for our stock appreciation rights for the year ended December 31, 2014 (unit data in thousands):
	Number			Weighted-			Weighted-			Aggregate
	of			Average			Average			Intrinsic
	Units			Exercise			Remaining			Value
				Price			Contractual			(in  millions)
							Term
Outstanding at beginning of period		96		$	26.35
Granted		66			32.69
Exercised		(15	)		26.07
Cancelled/expired/forfeited		(44	)		30.28
Outstanding at end of period		103		$	28.72			5.4 Years		$	0.3
Exercisable at end of period		40		$	26.35			5.0 Years		$	0.2
The aggregate intrinsic value included in the table above represents the total pretax intrinsic value that would have been received by the stock appreciation rights holders had all holders exercised their rights on December 31, 2014. The intrinsic value is calculated as the total number of stock appreciation rights multiplied by the difference between the closing price of our common stock on the last trading day of the period and the exercise price of the stock appreciation rights. This amount changes based on the price of our common stock.
The weighted-average fair value as of December 31, 2014 for stock appreciation rights granted for the years ended December 31, 2014, 2013 and 2012 was $3.21, $3.95 and $4.16, respectively. The fair value is re-determined at the end of each reporting period for purposes of remeasuring compensation expense associated with these cash-settled awards.
Cash-Settled Performance Units
Nonvested cash-settled performance units as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (unit data in thousands):
	Number			Weighted-
	of			Average
	Units			Fair  Value
Nonvested at beginning of period		51
Adjustment to assumed vesting percentage		(21	)
Granted		34
Vested		—
Cancelled/forfeited		(27	)
Nonvested at end of period		37		$	30.3
For performance units granted prior to 2014, the actual number of units in which each participant vests is dependent upon achievement of certain Return on Invested Capital and Diluted Earnings Per Share targets over three-year performance periods. With respect to performance units granted during 2014, the actual number of units in which each participant vests is dependent upon those same targets as well as an additional Relative Total Shareholder Return target comparing B&W stock price performance to that of a custom peer group, over a three-year performance period. The number of units in which participants can vest ranges from zero to 200% of the initial performance units granted, to be determined upon completion of the three-year performance period. The nonvested shares at the end of the period in the table above assumes weighted-average vesting of 58%.
The weighted-average fair value for these cash-settled awards is based on our closing stock price as of December 31, 2014. The fair value is re-determined at the end of each reporting period for purposes of remeasuring compensation expense associated with these cash-settled awards.
Cash-Settled Restricted Stock Units
Nonvested restricted stock units as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (unit data in thousands):
	Number			Weighted-
	of			Average
	Units			Fair  Value
Nonvested at beginning of period		23
Granted		12
Vested		(13	)
Cancelled/forfeited		(9	)
Nonvested at end of period		13		$	30.3
The weighted-average fair value for these cash-settled awards is based on our closing stock price as of December 31, 2014. The fair value is re-determined at the end of each reporting period for purposes of remeasuring compensation expense associated with these cash-settled awards.
Thrift Plan
On August 13, 2010, 5,000,000 of the authorized and unissued shares of B&W common stock were reserved for issuance for the employer match to the Thrift Plan. Those matching employer contributions equal 50% of the first 6% of compensation, as defined in the Thrift Plan, contributed by participants, and fully vest and are nonforfeitable after three years of service or upon retirement, death, lay-off or approved disability. The Thrift Plan allows employees to sell their interest in B&W’s common stock fund at any time, except as limited by applicable securities laws and regulations. During the year ended December 31, 2014, we issued 436,246 shares of B&W’s common stock as employer contributions pursuant to the Thrift Plan. At December 31, 2014, 2,820,973 shares of B&W’s common stock remained available for issuance under the Thrift Plan.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 10 – COMMITMENTS AND CONTINGENCIES
	Investigations and Litigation
	Apollo and Parks Township
	In January 2010, Michelle McMunn, Cara D. Steele and Yvonne Sue Robinson filed suit against Babcock & Wilcox Power Generation Group, Inc. (“B&W PGG”), Babcock & Wilcox Technical Services Group, Inc., formerly known as B&W Nuclear Environmental Services, Inc. (the “B&W Parties”) and Atlantic Richfield Company (“ARCO”) in the United States District Court for the Western District of Pennsylvania. Since January 2010, additional suits have been filed by additional plaintiffs and there are currently sixteen lawsuits pending in the U.S. District Court for the Western District of Pennsylvania against the B&W Parties and ARCO, including the most recent claim filed in January 2015. In total, the suits presently involve approximately 94 primary claimants. The primary claimants allege, among other things, personal injuries and property damage as a result of alleged releases of radioactive material relating to the operation, remediation, and/or decommissioning of two former nuclear fuel processing facilities located in the Borough of Apollo and Parks Township, Pennsylvania (collectively, the “Apollo and Parks Litigation”). Those facilities previously were owned by Nuclear Materials and Equipment Company, a former subsidiary of ARCO (“NUMEC”), which was acquired by B&W PGG. The plaintiffs in the Apollo and Parks Litigation seek compensatory and punitive damages, and in November 2014 delivered a demand of $125.0 million for the settlement of all then-filed actions. All of the suits, except for the most recent filing, have been consolidated for non-dispositive pre-trial matters. Fact discovery in the Apollo and Parks Litigation is now closed for all claims other than the most recent claim in January 2015, but no trial date has been set.
	At the time of ARCO’s sale of NUMEC stock to B&W PGG, B&W PGG received an indemnity and hold harmless agreement from ARCO with respect to claims and liabilities arising prior to or as a result of conduct or events predating the acquisition.
	Insurance coverage and/or the ARCO indemnity currently provides coverage for the claims alleged in the Apollo and Parks Litigation, although no assurance can be given that insurance and/or the indemnity will be available or sufficient in the event of liability, if any.
	The B&W Parties and ARCO were defendants in a prior litigation filed in 1994 relating to the operation of the Apollo Borough and Parks Township facilities in the matter of Donald F. Hall and Mary Ann Hall, et al., v. Babcock & Wilcox Company, et al. (the “Hall Litigation”). In 1998, the B&W Parties settled all then-pending and future punitive damage claims in the Hall Litigation for $8.0 million and sought reimbursement from third parties, including its insurers, American Nuclear Insurers and Mutual Atomic Energy Liability Underwriters (“ANI”). In 2008, ARCO settled the Hall Litigation with the plaintiffs for $27.5 million. The B&W Parties then settled the Hall Litigation in 2009 for $52.5 million, settling approximately 250 personal injury and wrongful death claims, as well as approximately 125 property damage claims, alleging damages as a result of alleged releases involving the facilities. ARCO and the B&W Parties retained their insurance rights against ANI in their respective settlements; however, under a related settlement regarding ARCO’s indemnification of B&W PGG relating to the two facilities, ARCO assigned to the B&W Parties 58.33% of the total of all ARCO’s proceeds/amounts recovered against ANI on account of the Hall Litigation.
	The B&W Parties sought recovery from ANI for amounts paid by the B&W Parties to settle the Hall Litigation, along with unreimbursed attorney fees, allocated amounts assigned by ARCO to the B&W Parties, and applicable interest based upon ANI’s breach of contract and bad faith conduct in the matter of The Babcock & Wilcox Company et al. v. American Nuclear Insurers, et al. (the “ANI Litigation”). ARCO also sought recovery against ANI in the ANI Litigation, which has been pending before the Court of Common Pleas of Allegheny County, Pennsylvania.
	In September 2011, a jury returned a verdict in the ANI Litigation, finding that the B&W Parties’ settlement of the Hall Litigation for $52.5 million and ARCO’s settlement for $27.5 million were fair and reasonable. Following the verdict, in February 2012, the B&W Parties, ARCO and ANI entered into an agreement in which the parties agreed to the dismissal with prejudice of all remaining claims pending in the ANI Litigation, excluding the B&W Parties’ and ARCO’s claims seeking reimbursement from ANI for the $52.5 million and $27.5 million settlements (plus interest) (the “Settlement Claims”). By agreement, ANI also waived: (1) any and all rights to appeal the September 2011 jury verdict on the basis of the trial court’s evidentiary rulings; and (2) any defenses and arguments of any kind except ANI’s position that it was not required to reimburse the B&W Parties’ and ARCO for their settlements under the provisions of the ANI policies. In February 2012, the Court granted the parties’ proposed order implementing their agreement and entered final judgment in favor of the B&W Parties and ARCO on the Settlement Claims. As part of the final order and judgment, the Court ruled that the B&W Parties and ARCO are entitled to pre-judgment interest on their $52.5 million and $27.5 million settlements, in the amounts of approximately $8.8 million and $6.2 million, respectively. In addition, post-verdict interest from the date of the jury verdict was awarded at 6%. In March 2012, ANI filed a notice of appeal as to the final judgment and a supersedeas appeal bond in the amount of 120% of the total final judgment amount. The parties filed their respective briefs with the Superior Court and oral arguments were held October 31, 2012.
	In July 2013, the Superior Court reversed the judgment of the trial court with instructions to reconsider the issue of the Settlement Claims under a different standard. In August 2013, B&W and ARCO filed a request for appeal of the Superior Court’s decision to the Pennsylvania Supreme Court. On January 24, 2014, the Supreme Court of Pennsylvania granted B&W and ARCO’s request for appeal. The parties’ briefs on the appeal have been filed and oral arguments were held October 7, 2014. B&W has not recognized any amounts claimed in the ANI Litigation in its financial statements due to the uncertainty surrounding the ultimate amount to be realized.
	Berlin Station
	Our subsidiary, Babcock & Wilcox Construction Co., Inc. (“BWCC”), is currently in a dispute with a customer in connection with a 75MW biomass-energy power plant that BWCC designed and built in Berlin, New Hampshire. The dispute primarily concerns material claims by BWCC against its customer for contract changes relating to schedule delays, delay costs, extra work, withheld payments, improper draws on letters of credit and withheld contract-retention amounts. The customer has made nine partial draws totaling approximately $11.0 million under letters of credit that were outstanding in connection with the project. These draws correspond to a total of approximately $11.9 million in alleged liquidated damages for delay (“Delay LDs”) on the project.
	Following the customer’s denial of BWCC’s change order request relating to schedule delays, delay costs and extra work incurred up to that time, on January 16, 2014, BWCC filed suit against the customer in the Court of Common Pleas, Summit County, Ohio, Case No. 2014 01 0208, seeking damages in excess of $37 million (the “Ohio suit”). On or about January 30, 2014, BWCC’s customer filed suit against BWCC in the Superior Court of Coos County, New Hampshire, Case No. 214-2014-CV-14 alleging breach of contract and seeking unspecified amounts (the “New Hampshire suit”). On June 26, 2014, the Ohio suit was dismissed on jurisdictional and forum non conveniens grounds. On August 29, 2014, BWCC filed its Answer, Affirmative Defenses and Counterclaim in the New Hampshire suit seeking recovery of damages incurred to date of at least $66 million in connection with all matters currently in dispute.
	There is a risk that the customer will attempt to call all or part of the remaining $21.9 million of letters of credit during the pendency of this matter. We believe any such call would be wrongful and entitle us to return of the funds and other damages. We have made provisions in our financial statements as disclosed in Note 1 for Delay LDs called to date against the letters of credit and have not recorded offsetting claims revenue related to these calls in our financial statements.
	We believe BWCC has sound legal and factual bases for its claims. BWCC intends to aggressively pursue recovery on its claims, including recovery of the wrongful calls against BWCC’s letters of credit. However, it is premature to predict the outcome of this matter. The litigation could be lengthy, and if BWCC’s customer were to prevail completely or substantially in this matter, the outcome could have a material adverse effect on our financial statements.
	Prairie Island
	On November 12, 2014, one of our subsidiaries, Babcock & Wilcox Nuclear Energy, Inc. (“B&W NE”), filed suit in the District Court, 1st JDC, Goodhue County Minnesota, Docket No. 25.cv.14.2626, against both Northern States Power Co. d/b/a Xcel Energy (“Xcel”) and SNC-Lavalin claiming $45.4 million in damages along with interest and attorneys’ fees for breach of contract and pursuant to a previously filed mechanic’s lien on Xcel’s property. The suit arises from a steam generator replacement project at Xcel’s Prairie Island Nuclear Generating Plant in Red Wing, Minnesota in which B&W NE served as subcontractor to SNC-Lavalin. B&W NE’s claims assert, among other things, that amounts owed to B&W NE have been improperly withheld and that Xcel was not entitled to impose certain liquidated damages for delay under the terms of B&W NE’s contract. As of December 31, 2014, Xcel and SNC-Lavalin have filed answers and limited counterclaims, but B&W NE believes the counterclaims are without merit.
	New Mexico Environment Department
	One of our subsidiaries owns a 30% interest in a joint venture, Nuclear Waste Partnership, LLC (“NWP”), which is executing a prime contract with the DOE for the management and operation of the DOE’s Waste Isolation Pilot Plant in Carlsbad, New Mexico (the “WIPP”). Another of our subsidiaries owns a 13% interest in a separate joint venture, Los Alamos National Security, LLC (“LANS”), which is executing a prime contract with the DOE/NNSA for the management and operation of the DOE’s Los Alamos National Laboratory (“Los Alamos”). On December 6, 2014, the DOE and each of its contractors, NWP and LANS, received Administrative Compliance Orders from the New Mexico Environment Department alleging violations of New Mexico environmental laws and regulations at both WIPP and Los Alamos associated with radiological incidents that occurred at the WIPP in February 2014. The Administrative Compliance Orders assessed civil penalties of approximately $17.75 million on the DOE and NWP and approximately $36.6 million on the DOE and LANS for the alleged violations at both the WIPP and Los Alamos. The DOE and the two joint ventures are pursuing negotiations with the New Mexico Environment Department over the alleged violations and proposed penalties. If civil penalties are ultimately imposed on the DOE, NWP and LANS for these incidents, either NWP or LANS, or both, may be required to pay civil penalties to the State of New Mexico and may be required to reimburse the DOE for a portion of such penalties assessed against the DOE by the State of New Mexico under the terms of their respective contracts with the DOE, in which case our subsidiaries may be required to make additional contributions to these joint ventures.
	Other Litigation and Settlements
	On December 17, 2014, an unfavorable jury verdict was delivered against The Babcock & Wilcox Company, Babcock & Wilcox Power Generation Group, Inc. Babcock & Wilcox Nuclear Energy and Babcock & Wilcox Canada Ltd. in a case entitled AREVA NP, INC. f/k/a Framatome ANP, Inc. v. The Babcock & Wilcox Company, et. al. in the amount of approximately $16 million. We strongly disagree with the verdict and believe the plaintiff’s claims are without merit. We have filed a post-trial motion requesting that the verdict be set aside or a new trial granted. Depending on the outcome of that proceeding we are evaluating our additional remedies, including a possible appeal to the Supreme Court of Virginia.
	The case was filed August 26, 2011 in the Circuit Court for the City of Lynchburg, Commonwealth of Virginia and alleged that the B&W parties to the suit owed royalties on certain commercial nuclear contracts performed by the Company and certain of its subsidiaries since 2004. As a result of the jury’s decision and notwithstanding our evaluation of post-trial remedies, we have made provisions in our financial statements for the full amount of the jury award.
	Additionally, due to the nature of our business, we are, from time to time, involved in routine litigation or subject to disputes or claims related to our business activities, including, among other things:
		•		performance- or warranty-related matters under our customer and supplier contracts and other business arrangements; and
		•		workers’ compensation claims, premises liability claims and other claims.
	Based upon our prior experience, we do not expect that any of these other litigation proceedings, disputes and claims will have a material adverse effect on our consolidated financial condition, results of operations or cash flows.
	Environmental Matters
	We have been identified as a potentially responsible party at various cleanup sites under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (“CERCLA”). CERCLA and other environmental laws can impose liability for the entire cost of cleanup on any of the potentially responsible parties, regardless of fault or the lawfulness of the original conduct. Generally, however, where there are multiple responsible parties, a final allocation of costs is made based on the amount and type of wastes disposed of by each party and the number of financially viable parties, although this may not be the case with respect to any particular site. We have not been determined to be a major contributor of wastes to any of these sites. On the basis of our relative contribution of waste to each site, we expect our share of the ultimate liability for the various sites will not have a material adverse effect on our consolidated financial condition, results of operations or cash flows in any given year.
	The Department of Environmental Protection of the Commonwealth of Pennsylvania (“PADEP”) advised us in March 1994 that it would seek monetary sanctions and remedial and monitoring relief related to the former production facility located in Parks Township, Pennsylvania (the “Parks Facility”). The relief sought was related to potential groundwater contamination resulting from previous operations at the facility. The Parks Facility was decommissioned in the 1990s, including facilities dismantlement and soil restoration. The NRC terminated the Parks Facility license in 2004 and released the facility for unrestricted use. What remains of the Parks Facility is currently owned by a subsidiary in our Nuclear Operations segment. Based on favorable results from groundwater sampling completed by our Nuclear Operations segment, we have sought approval by PADEP for release of the property, subject to limitations on future use, under Pennsylvania’s voluntary clean-up program.
	We perform significant amounts of work for the U.S. Government under both prime contracts and subcontracts and operate certain facilities that are licensed to possess and process special nuclear materials. As a result of these activities, we are subject to continuing reviews by governmental agencies, including the U.S. Environmental Protection Agency and the NRC.
	The NRC’s decommissioning regulations require our Nuclear Operations segment to provide financial assurance that it will be able to pay the expected cost of decommissioning each of its licensed facilities at the end of its service life. We provided financial assurance aggregating $44.2 million during the year ended December 31, 2014 with existing letters of credit for the ultimate decommissioning of these licensed facilities. These two facilities have provisions in their government contracts pursuant to which substantially all of our decommissioning costs and financial assurance obligations are covered by the DOE, including the costs to complete the decommissioning projects underway at the facility in Erwin, Tennessee. These letters of credit are to cover decommissioning required pursuant to work not subject to this DOE obligation.
	Our compliance with U.S. federal, state and local environmental control and protection regulations resulted in pretax charges of approximately $13.6 million in the year ended December 31, 2014. In addition, compliance with existing environmental regulations necessitated capital expenditures of $0.3 million in the year ended December 31, 2014. At December 31, 2014 and 2013, we had total environmental accruals (including provisions for the facilities discussed above) of $59.9 million and $58.1 million, respectively. Of our total environmental accruals at December 31, 2014 and 2013, $3.6 million and $4.7 million, respectively, were included in current liabilities. Inherent in the estimates of those accruals and recoveries are our expectations regarding the levels of contamination, decommissioning costs and recoverability from other parties, which may vary significantly as decommissioning activities progress. Accordingly, changes in estimates could result in material adjustments to our operating results, and the ultimate loss may differ materially from the amounts that we have provided for in our consolidated financial statements.
	Operating Leases
	Future minimum payments required under operating leases that have initial or remaining noncancellable lease terms in excess of one year at December 31, 2014 are as follows (in thousands):
	Fiscal Year Ending December 31,		Amount
	2015		$	9,896
	2016		$	7,049
	2017		$	6,067
	2018		$	4,956
	2019		$	3,489
	Thereafter		$	1,221
	Total rental expense for the years ended December 31, 2014, 2013 and 2012 was $12.5 million, $11.6 million and $12.1 million, respectively. These expense amounts include contingent rentals and are net of sublease income, neither of which is material.

Risks_and_Uncertainties

Risks and Uncertainties	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Risks and Uncertainties	NOTE 11 – RISKS AND UNCERTAINTIES
	Percentage-of-Completion Accounting
	As of December 31, 2014, in accordance with the percentage-of-completion method of accounting, we have provided for our estimated costs to complete all of our ongoing contracts. However, it is possible that current estimates could change due to unforeseen events, which could result in adjustments to overall contract costs. The risk on fixed-priced contracts is that revenue from the customer does not cover increases in our costs. It is possible that current estimates could materially change for various reasons, including, but not limited to, fluctuations in forecasted labor productivity or steel and other raw material prices. Increases in costs on our fixed-price contracts could have a material adverse impact on our consolidated financial condition, results of operations and cash flows. Alternatively, reductions in overall contract costs at completion could materially improve our consolidated financial condition, results of operations and cash flows.
	Insurance
	Upon the February 22, 2006 effectiveness of the settlement relating to the Chapter 11 proceedings involving several of our subsidiaries, most of our subsidiaries contributed substantial insurance rights to the asbestos personal injury trust, including rights to (1) certain pre-1979 primary and excess insurance coverages and (2) certain of our 1979-1986 excess insurance coverage. These insurance rights provided coverage for, among other things, asbestos and other personal injury claims, subject to the terms and conditions of the policies. The contribution of these insurance rights was made in exchange for the agreement on the part of the representatives of the asbestos claimants, including the representative of future claimants, to the entry of a permanent injunction, pursuant to Section 524(g) of the U.S. Bankruptcy Code, to channel to the asbestos trust all asbestos-related claims against our subsidiaries and former subsidiaries arising out of, resulting from or attributable to their operations, and the implementation of related releases and indemnification provisions protecting those subsidiaries and their affiliates from future liability for such claims. Although we are not aware of any significant, unresolved claims against our subsidiaries and former subsidiaries that are not subject to the channeling injunction and that relate to the periods during which such excess insurance coverage related, with the contribution of these insurance rights to the asbestos personal injury trust, it is possible that we could have underinsured or uninsured exposure for non-derivative asbestos claims or other personal injury or other claims that would have been insured under these coverages had the insurance rights not been contributed to the asbestos personal injury trust.

Financial_Instruments_with_Con

Financial Instruments with Concentrations of Credit Risk	12 Months Ended
	Dec. 31, 2014
Risks and Uncertainties [Abstract]
Financial Instruments with Concentrations of Credit Risk	NOTE 12 – FINANCIAL INSTRUMENTS WITH CONCENTRATIONS OF CREDIT RISK
	Our Power Generation and Nuclear Energy segments’ major customers are large utilities. The primary customer of our Nuclear Operations segment is the U.S. Government, including some of its contractors. These concentrations of customers may impact our overall exposure to credit risk, either positively or negatively, in that our customers may be similarly affected by changes in economic or other conditions. In the years ended December 31, 2014, 2013 and 2012, the U.S. Government accounted for approximately 45%, 38% and 34%, respectively, of our total revenues. Accounts receivable due directly or indirectly from the U.S. Government represented 25% and 20% of net receivables at December 31, 2014 and December 31, 2013, respectively. See Note 16 for additional information about our operations in different geographic areas.
	We believe that our provision for possible losses on uncollectible accounts receivable is adequate for our credit loss exposure. At December 31, 2014 and 2013, the allowance for possible losses that we deducted from accounts receivable – trade on the accompanying consolidated balance sheets was $13.7 million and $3.6 million, respectively.

Investments

Investments	12 Months Ended
	Dec. 31, 2014
Investments Schedule [Abstract]
Investments	NOTE 13 – INVESTMENTS
	The following is a summary of our investments at December 31, 2014:
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair  Value
				Gains		Losses
		(In thousands)
	Trading securities
	Corporate bonds – Centrus Energy Corp.	$	2,628	$	—	$	(189	)	$	2,439
	Available-for-sale securities
	Equities – Centrus Energy Corp.	$	3,088	$	—	$	—		$	3,088
	Mutual funds		3,906		293		—			4,199
	Asset-backed securities and collateralized mortgage obligations		370		—		(51	)		319
	Commercial paper		2,398		—		—			2,398
	Total	$	12,390	$	293	$	(240	)	$	12,443
	The following is a summary of our available-for-sale securities at December 31, 2013:
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair  Value
				Gains		Losses
		(In thousands)
	U.S. Government and agency securities	$	2,999	$	1	$	—		$	3,000
	Mutual funds		3,752		249		—			4,001
	Asset-backed securities and collateralized mortgage obligations		472		8		(55	)		425
	Commercial paper		7,748		—		—			7,748
	Total	$	14,971	$	258	$	(55	)	$	15,174
	Proceeds, gross realized gains and gross realized losses on sales of available-for-sale securities is as follows:
		Proceeds		Gross		Gross
				Realized  Gains		Realized  Losses
		(In thousands)
	Year Ended December 31, 2014	$	32,089	$	172	$	—
	Year Ended December 31, 2013	$	168,879	$	1,127	$	—
	Year Ended December 31, 2012	$	247,649	$	35	$	—

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	NOTE 14 – DERIVATIVE FINANCIAL INSTRUMENTS
	We have designated all of our FX forward contracts that qualify for hedge accounting as cash flow hedges. The hedged risk is the risk of changes in functional-currency-equivalent cash flows attributable to changes in FX spot rates of forecasted transactions related to long-term contracts. We exclude from our assessment of effectiveness the portion of the fair value of the FX forward contracts attributable to the difference between FX spot rates and FX forward rates. At December 31, 2014, we had deferred approximately $0.1 million of net losses on these derivative financial instruments in accumulated other comprehensive income. Assuming market conditions continue, we expect to recognize substantially all of this amount in the next twelve months.
	At December 31, 2014, our derivative financial instruments consisted of FX forward contracts. The notional value of our FX forward contracts totaled $74.2 million at December 31, 2014, with maturities extending to December 2016. These instruments consist primarily of contracts to purchase or sell Canadian Dollars. We are exposed to credit-related losses in the event of nonperformance by counterparties to derivative financial instruments. We attempt to mitigate this risk by using major financial institutions with high credit ratings. The counterparties to all of our FX forward contracts are financial institutions included in our credit facility. Our hedge counterparties have the benefit of the same collateral arrangements and covenants as described under our credit facility.
	The following tables summarize our derivative financial instruments at December 31, 2014 and 2013:
		Asset and Liability Derivatives
		December 31,
		2014			2013
		(In thousands)
	Derivatives Designated as Hedges:
	Foreign Exchange Contracts:
	Location
	Accounts receivable-other	$	541		$	1,139
	Other assets	$	—		$	94
	Accounts payable	$	2,744		$	581
	Other liabilities	$	743		$	603
	Derivatives Not Designated as Hedges:
	Foreign Exchange Contracts:
	Location
	Accounts receivable-other	$	176		$	464
	Other assets	$	—		$	50
	Accounts payable	$	284		$	10
	The effects of derivatives on our financial statements are outlined below:
		December 31,
		2014			2013
		(In thousands)
	Derivatives Designated as Hedges:
	Cash Flow Hedges:
	Foreign Exchange Contracts:
	Amount of loss recognized in other comprehensive income	$	(3,184	)	$	(5,936	)
	Gain (loss) reclassified from accumulated other comprehensive income into earnings: effective portion
	Location
	Revenues	$	620		$	(1,885	)
	Cost of operations	$	(2,793	)	$	(2,174	)
	Other-net	$	4		$	144
	Loss recognized in income: portion excluded from effectiveness testing
	Location
	Other-net	$	(104	)	$	(349	)
	Derivatives Not Designated as Hedges:
	Forward Contracts:
	Gain (loss) recognized in income
	Location
	Other-net	$	(184	)	$	96

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 15 – FAIR VALUE MEASUREMENTS
	FASB Topic Fair Value Measurements and Disclosures defines fair value 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 at the measurement date. This topic also sets forth the disclosure requirements regarding fair value and establishes a hierarchy for valuation inputs that emphasizes the use of observable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The fair value hierarchy established by this topic is as follows:
		•		Level 1 – inputs are based upon quoted prices for identical instruments traded in active markets.
		•		Level 2 – inputs are based upon quoted prices for similar instruments in active markets, quoted prices for similar or identical instruments in inactive markets and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets and liabilities.
		•		Level 3 – inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models and similar valuation techniques.
	The following sections describe the valuation methodologies we use to measure the fair values of our investments, derivatives and nonrecurring fair value measurements.
	Investments
	Investments primarily include U.S. Government and agency securities, money-market funds, mortgage-backed securities and shares of Centrus Energy Corp. common stock and bonds acquired through the reorganization of USEC Inc., as discussed below.
	In general, and where applicable, we principally use a composite of observable prices and quoted prices in active markets for identical assets or liabilities to determine fair value. This pricing methodology applies to our Level 1 and Level 2 investments.
	Our investments are currently in an unrealized gain position totaling approximately $0.1 million at December 31, 2014. At December 31, 2013, we had an unrealized gain on our investments totaling approximately $0.2 million. Based on our analysis of these investments, we believe that none of our investments were other than temporarily impaired at December 31, 2014.
	Centrus Energy Corp. Transaction
	On September 5, 2014, the Bankruptcy Court for the District of Delaware approved and confirmed the proposed voluntary Chapter 11 pre-packaged or pre-arranged plan of reorganization of USEC Inc. (the “Plan”). USEC Inc. completed the final steps necessary to emerge from its Chapter 11 bankruptcy on September 30, 2014. The reorganized company is called Centrus Energy Corp. and trades on the New York Stock Exchange under the trading symbol LEU. Under the Plan, B&W received 7.98% of the Centrus Energy Corp. common stock and approximately $20.2 million in principal amount of 8.0% PIK Toggle Notes due 2019/2024 in exchange for its investment in USEC Series B-1 12.75% Convertible Preferred Stock and Warrants that we wrote off through impairments of $19.1 million and $27.0 million in the years ended December 31, 2013 and 2012, respectively. We recorded a gain in other income of $18.6 million in the third quarter of 2014 for the fair value of the Centrus Energy Corp. common stock and notes, which were trading at a discount to par value. We recognized an other than temporary impairment of $4.2 million on our Centrus Energy Corp. common stock in the fourth quarter of 2014 due to the severity of its decline in market value since its emergence from bankruptcy on September 30, 2014.
	Fair Value Measurements
	The following is a summary of our investments measured at fair value at December 31, 2014:
			12/31/14		Level 1		Level 2		Level 3
			(In thousands)
	Trading securities
	Corporate bonds – Centrus Energy Corp.		$	2,439	$	2,439	$	—	$	—
	Available-for-sale securities
	Equities – Centrus Energy Corp.		$	3,088	$	—	$	3,088	$	—
	Mutual funds			4,199		—		4,199		—
	Asset-backed securities and collateralized mortgage obligations			319				319		—
	Commercial paper			2,398				2,398		—
	Total		$	12,443	$	2,439	$	10,004	$	—
	The following is a summary of our available-for-sale securities measured at fair value at December 31, 2013:
			12/31/13		Level 1		Level 2		Level 3
			(In thousands)
	Mutual funds		$	4,001	$	—	$	4,001	$	—
	U.S. Government and agency securities			3,000		3,000		—		—
	Asset-backed securities and collateralized mortgage obligations			425		—		425		—
	Commercial paper			7,748		—		7,748		—
	Total		$	15,174	$	3,000	$	12,174	$	—
	Derivatives
	Level 2 derivative assets and liabilities currently consist of FX forward contracts. Where applicable, the value of these derivative assets and liabilities is computed by discounting the projected future cash flow amounts to present value using market-based observable inputs, including FX forward and spot rates, interest rates and counterparty performance risk adjustments. At December 31, 2014 and 2013, we had forward contracts outstanding to purchase or sell foreign currencies, primarily Canadian Dollars, with a total fair value of $(3.1) million and $0.6 million, respectively.
	Other Financial Instruments
	We used the following methods and assumptions in estimating our fair value disclosures for our other financial instruments, as follows:
	Cash and cash equivalents and restricted cash and cash equivalents. The carrying amounts that we have reported in the accompanying consolidated balance sheets for cash and cash equivalents and restricted cash and cash equivalents approximate their fair values due to their highly liquid nature.
	Long- and short-term debt. We base the fair values of debt instruments on quoted market prices. Where quoted prices are not available, we base the fair values on the present value of future cash flows discounted at estimated borrowing rates for similar debt instruments or on estimated prices based on current yields for debt issues of similar quality and terms. The fair value of our debt instruments approximated their carrying value at December 31, 2014 and December 31, 2013.
	Guarantee. In the third quarter of 2014, B&W issued a letter of credit with a four year term totaling approximately $10 million in support of a bank loan borrowed by Thermax Babcock & Wilcox Energy Solutions Private Limited (“TBWES”). TBWES is an unconsolidated affiliate and the letter of credit can be drawn if TBWES defaults on the loan. We recognized the fair value of this guarantee totaling $1.7 million in other liabilities on our consolidated balance sheet at December 31, 2014 with an associated increase to our investments in unconsolidated affiliates.

Segment_Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Reporting	NOTE 16 – SEGMENT REPORTING
	Our reportable segments are Power Generation, Nuclear Operations, Technical Services, Nuclear Energy and mPower, as described in Note 1.
	The operations of our segments are managed separately and each has unique technology, services and customer class. We account for intersegment sales at prices that we generally establish by reference to similar transactions with unaffiliated customers. Reportable segments are measured based on operating income exclusive of general corporate expenses, contract and insurance claims provisions, legal expenses, gains (losses) on sales of corporate assets, special charges for restructuring activities and mark to market charges related to our pension and postretirement benefit plans.
	1. Information about Operations in our Different Industry Segments:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	REVENUES (1):
	Power Generation		$	1,486,029		$	1,767,651		$	1,785,959
	Nuclear Operations			1,220,952			1,167,683			1,098,031
	Technical Services			84,834			104,254			107,851
	Nuclear Energy			154,721			283,857			325,655
	mPower			278			1,523			326
	Adjustments and Eliminations			(23,795	)		(55,760	)		(26,463	)
			$	2,923,019		$	3,269,208		$	3,291,359
	(1)	Segment revenues are net of the following intersegment transfers and other adjustments:
	Power Generation Transfers		$	5,896		$	37,552		$	7,932
	Nuclear Operations Transfers			9,922			6,773			6,015
	Technical Services Transfers			57			3,817			3,496
	Nuclear Energy Transfers			7,920			7,618			8,992
	mPower Transfers			—			—			28
			$	23,795		$	55,760		$	26,463
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	OPERATING INCOME:
	Power Generation		$	98,557		$	155,837		$	183,387
	Nuclear Operations			270,536			237,855			226,269
	Technical Services			35,203			58,234			59,655
	Nuclear Energy			(23,211	)		8,641			50,649
	mPower			(68,946	)		(81,304	)		(113,528	)
			$	312,139		$	379,263		$	406,432
	Unallocated Corporate(1)			(32,514	)		(26,039	)		(27,953	)
	Special Charges for Restructuring Activities			(41,091	)		(39,599	)		—
	Mark to Market Adjustment			(241,156	)		222,737			(31,890	)
	Total Operating Income(2)		$	(2,622	)	$	536,362		$	346,589
	Other Income (Expense):
	Interest income			1,028			1,443			1,491
	Interest expense			(7,579	)		(3,115	)		(3,735	)
	Other - net			14,639			(17,517	)		(24,927	)
	Total Other Expense			8,088			(19,189	)		(27,171	)
	Income before Provision for Income Taxes		$	5,466		$	517,173		$	319,418
	(1)        Unallocated corporate includes general corporate overhead not allocated to segments
	(2)        Included in operating income is the following:
	(Gains) Losses on Asset Disposals – Net:
	Power Generation		$	1,752		$	1,181		$	3,276
	Nuclear Operations			—			163			(339	)
	Technical Services			—			—			(1,517	)
	Nuclear Energy			(665	)		(28	)		(1	)
	mPower			—			—			—
	Unallocated Corporate			(6	)		(267	)		—
			$	1,081		$	1,049		$	1,419
	Equity in Income of Investees:
	Power Generation		$	8,682		$	18,388		$	17,402
	Nuclear Operations			—			—			—
	Technical Services			33,042			50,281			49,621
	Nuclear Energy			32			(611	)		(314	)
	mPower			—			—			—
			$	41,756		$	68,058		$	66,709
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	SEGMENT ASSETS:
	Power Generation		$	1,018,149		$	970,718		$	1,059,824
Nuclear Operations			770,359			778,203			708,607
Technical Services			114,581			120,559			125,494
Nuclear Energy			427,412			439,325			391,096
mPower			17,233			21,790			10,137
Total Segment Assets			2,347,734			2,330,595			2,295,158
Corporate Assets			509,202			278,558			545,197
Total Assets		$	2,856,936		$	2,609,153		$	2,840,355
CAPITAL EXPENDITURES:
Power Generation		$	15,449		$	15,280		$	24,592
Nuclear Operations			34,777			31,572			44,810
Technical Services			66			98			—
Nuclear Energy			14,358			5,506			5,881
mPower			1,983			2,854			2,554
Segment Capital Expenditures			66,633			55,310			77,837
Corporate Capital Expenditures			9,396			9,640			8,798
Total Capital Expenditures		$	76,029		$	64,950		$	86,635
DEPRECIATION AND AMORTIZATION:
Power Generation		$	30,661		$	23,892		$	19,126
Nuclear Operations			54,524			26,975			32,013
Technical Services			3			185			244
Nuclear Energy			6,564			6,520			5,923
mPower			974			554			279
Segment Depreciation and Amortization			92,726			58,126			57,585
Corporate Depreciation and Amortization			13,072			12,399			12,112
Total Depreciation and Amortization		$	105,798		$	70,525		$	69,697
INVESTMENT IN UNCONSOLIDATED AFFILIATES:
Power Generation		$	109,248		$	144,475		$	139,399
Nuclear Operations			—			—			—
Technical Services			31,229			40,329			46,928
Nuclear Energy			27			27			27
mPower			—			—			—
Total Investment in Unconsolidated Affiliates		$	140,504			184,831		$	186,354
2. Information about our Product and Service Lines:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
REVENUES:
Power Generation:
New Build Environmental Equipment		$	234,475		$	434,228		$	446,514
New Build Steam Generation Systems			358,539			454,277			511,201
Aftermarket Services			796,061			885,185			841,571
Industrial Environmental			105,400			—			—
Eliminations/Other			(8,446	)		(6,039	)		(13,327	)
			1,486,029			1,767,651			1,785,959
Nuclear Operations:
Nuclear Component Program			1,208,505			1,153,216			1,086,081
Commercial Operations			773			7,681			5,908
Eliminations/Other			11,674			6,786			6,042
			1,220,952			1,167,683			1,098,031
Technical Services:
Commercial Operations			10,897			21,227			20,819
Nuclear Environmental Services			70,998			73,043			78,228
Management & Operation Contracts of U.S. Government Facilities			2,939			9,984			8,804
Eliminations/Other			—			—			—
			84,834			104,254			107,851
Nuclear Energy:
Nuclear Services			105,078			113,180			158,365
Nuclear Equipment			41,354			83,449			134,011
Nuclear Projects			8,289			87,002			33,319
Eliminations/Other			—			226			(40	)
			154,721			283,857			325,655
mPower:			278			1,523			326
Eliminations			(23,795	)		(55,760	)		(26,463	)
		$	2,923,019		$	3,269,208		$	3,291,359
3. Information about our Consolidated Operations in Different Geographic Areas:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
REVENUES(1):
United States		$	2,308,987		$	2,589,521		$	2,615,387
Canada			193,786			313,881			288,246
Denmark			65,436			56,336			18,504
United Kingdom			61,972			20,927			6,653
China			59,841			58,775			45,830
Sweden			29,786			37,823			101,688
Dominican Republic			27,399			473			687
Germany			22,792			22,869			34,364
Chile			15,686			9,240			11,582
Korea			14,149			9,033			14,461
Thailand			8,113			2,650			3,041
Colombia			8,037			44,622			1,163
Saudi Arabia			8,003			8,200			7,973
Singapore			7,527			2,507			171
France			7,057			3,930			2,384
Indonesia			5,324			6,227			7,828
India			5,070			4,670			13,306
Finland			4,926			—			—
Vietnam			3,829			1,946			459
Italy			3,540			4,156			8,477
Poland			3,343			1,748			415
Norway			3,199			2,594			9,939
Brazil			3,156			2,751			2,585
South Africa			3,137			2,208			2,993
Argentina			3,100			5,737			23,529
Trinidad			2,546			3,264			2,401
Australia			2,540			1,854			1,251
Mexico			2,344			3,461			3,384
Israel			2,088			2,919			2,502
Venezuela			2,041			448			832
Other Countries			34,265			44,438			59,324
		$	2,923,019		$	3,269,208		$	3,291,359
(1)	We allocate geographic revenues based on the location of the customer’s operations.
NET PROPERTY, PLANT AND EQUIPMENT:
United States		$	366,288		$	367,672		$	363,447
Canada			27,480			38,738			45,402
China			12,356			10,980			7,926
Mexico			12,106			8,312			8,302
United Kingdom			8,638			9,414			9,714
Denmark			6,963			8,715			8,565
Germany			1,536			2,060			2,284
Other Countries			1,268			1,188			1,381
		$	436,635		$	447,079		$	447,021
4. Information about our Major Customers:
In the years ended December 31, 2014, 2013 and 2012, the U.S. Government accounted for approximately 45%, 38% and 34% of our total revenues, respectively. Substantially, these revenues are included in our Nuclear Operations and Technical Services segments.

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	NOTE 17 – QUARTERLY FINANCIAL DATA (UNAUDITED)
	The following tables set forth selected unaudited quarterly financial information for the years ended December 31, 2014 and 2013:
			Year Ended December 31, 2014
			Quarter Ended
			March 31,		June 30,		Sept. 30,		Dec. 31,
			2014		2014		2014		2014
			(In thousands, except per share amounts)
	Revenues		$	662,017	$	686,006	$	737,902	$	837,094
	Operating income (1)		$	53,640	$	35,118	$	65,160	$	(156,540	)
	Equity in income of investees		$	15,269	$	13,183	$	7,308	$	5,996
	Net income attributable to The Babcock & Wilcox Company		$	45,044	$	26,437	$	61,214	$	(103,307	)
	Earnings per common share:
	Basic:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.24	$	0.57	$	(0.97	)
	Diluted:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.24	$	0.57	$	(0.97	)
	(1)	Includes equity in income of investees.
			Year Ended December 31, 2013
			Quarter Ended
			March 31,		June 30,		Sept. 30,		Dec. 31,
			2013		2013		2013		2013
			(In thousands, except per share amounts)
	Revenues		$	805,423	$	886,136	$	774,834	$	802,815
	Operating income (1)		$	60,213	$	98,706	$	82,121	$	295,322
	Equity in income of investees		$	14,787	$	18,775	$	18,151	$	16,345
	Net income attributable to The Babcock & Wilcox Company		$	47,174	$	72,870	$	60,446	$	165,588
	Earnings per common share:
	Basic:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.65	$	0.54	$	1.5
	Diluted:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.65	$	0.54	$	1.48
	(1)	Includes equity in income of investees.
	Our March 31, 2014 quarter included contract losses of $7.6 million for additional costs to complete our Berlin Station project. Our September 30, 2014 quarter included a gain in other income of $18.6 million, with no related tax provision, for the receipt of Centrus Energy Corp. common stock and notes, which we received in exchange for our investment in USEC Inc. upon its emergence from Chapter 11 bankruptcy.
	Our June 30, 2013 quarter included contract losses of $30.2 million for additional estimated costs to complete our Berlin Station project. Our December 31, 2013 quarter included a $19.1 million impairment of our investment in USEC Inc. with no related tax benefit.
	We immediately recognize actuarial gains and losses for our pension and postretirement benefit plans into earnings in the fourth quarter of each year as a component of net periodic benefit cost. The effect of this adjustment, recorded in the quarters ended December 31, 2014 and 2013 on pre-tax income was $(230.5) million and $222.9 million, respectively. Additionally, in the quarter ended September 30, 2014, we recognized approximately $(11.1) million in pre-tax income because of the interim remeasurement requirements resulting from settlements of certain Canadian pension obligations. Included in the adjustment for the quarter ended December 31, 2013 is approximately $23 million ($17 million net of tax) of pension gains that should have been recognized in the quarter ended September 30, 2013 because of the interim remeasurement requirements resulting from settlements of certain Canadian pension obligations. The recognition of this amount in the quarter ended December 31, 2013 is not material to any interim period presented.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 18 – EARNINGS PER SHARE
	The following table sets forth the computation of basic and diluted earnings per share:
			Year Ended December 31,
			2014		2013		2012
			(In thousands, except shares and
			per share amounts)
	Basic:
	Net income attributable to The Babcock & Wilcox Company		$	29,388	$	346,078	$	227,695
	Weighted average common shares			108,477,262		111,901,750		118,418,930
	Basic earnings per common share:
	Net income attributable to The Babcock & Wilcox Company		$	0.27	$	3.09	$	1.92
	Diluted:
	Net income attributable to The Babcock & Wilcox Company		$	29,388	$	346,078	$	227,695
	Weighted average common shares (basic)			108,477,262		111,901,750		118,418,930
	Effect of dilutive securities:
	Stock options, restricted stock and performance shares(1)			283,830		783,667		602,394
	Adjusted weighted average common shares			108,761,092		112,685,417		119,021,324
	Diluted earnings per common share:
	Net income attributable to The Babcock & Wilcox Company		$	0.27	$	3.07	$	1.91
	-1	At December 31, 2014, 2013 and 2012, we excluded from the diluted share calculation 1,698,106, 442,226, and 1,082,904 shares, respectively, related to stock options, as their effect would have been antidilutive.

Basis_of_Presentation_and_Sign1

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Reportable Segments	Reportable Segments
	We operate in five reportable segments: Power Generation, Nuclear Operations, Technical Services, Nuclear Energy and mPower. Our reportable segments are further described as follows:
		•		Our Power Generation segment provides advanced fossil and renewable power generation equipment that includes a broad suite of boiler products and environmental systems and related services for power and industrial uses. We specialize in engineering, manufacturing, procurement, and erection of equipment and technologies used in the power generation industry and various other industries, and the provision of related services, including steam generating equipment, proven emissions control systems for environmental regulations, renewable energy solutions (biomass, combined heat and power, waste-to-energy and concentrating solar power), boiler cleaning systems, material transport equipment, fuel handling systems, cogeneration and combined cycle installations, and carbon capture and sequestration technologies. For this full range of product offerings, we offer complete aftermarket, operation and maintenance and construction project services. We provide products and services to electric utilities, municipalities, EPC contractors, architect engineers, independent power producers, international trading firms, electric power cooperatives and state electricity boards. Our markets include electric power generation, industrial, chemical, oil refinery, cement, institutional, municipal and government customers worldwide. We have an extensive North American and global footprint including engineering, design, service, manufacturing, sales, business development, regional service centers, manufacturers’ representatives and joint venture facilities located in more than 30 countries around the globe. Our installed base represents more than 300,000 MW of equivalent steam-generating capacity in more than 800 facilities in over 90 countries.
	Our steam generating equipment operates on a range of traditional fossil fuels including coal, natural gas and oil along with renewable, unconventional and other typical waste fuel streams. We have commercialized many advanced emissions technologies to control nitrogen oxide, sulfur dioxide, sulfur trioxide, coarse and fine particulate matter, mercury, acid gases and other hazardous air emissions.
	On June 20, 2014, we completed the acquisition of MEGTEC Holdings, Inc. (“MEGTEC”). MEGTEC designs, engineers, manufactures and services air pollution control systems and coating/drying equipment for a variety of industrial applications and complements our environmental products and solutions offerings.
		•		Our Nuclear Operations segment manufactures naval nuclear reactors for the U.S. Department of Energy (“DOE”)/National Nuclear Security Administration’s (“NNSA”) Naval Nuclear Propulsion Program, which in turn supplies them to the U.S. Navy for use in submarines and aircraft carriers. Through this segment, we own and operate manufacturing facilities located in Lynchburg, Virginia; Mount Vernon, Indiana; Euclid, Ohio; Barberton, Ohio; and Erwin, Tennessee. The Barberton and Mount Vernon locations specialize in the design and manufacture of heavy components. These two locations are N-Stamp certified by the American Society of Mechanical Engineers (“ASME”), making them two of only a few North American suppliers of large, heavy-walled nuclear components and vessels. The Euclid facility, which is also ASME N-Stamp certified, fabricates electro-mechanical equipment for the U.S. Government, and performs design, manufacturing, inspection, assembly and testing activities. The Lynchburg operations fabricate fuel-bearing precision components that range in weight from a few grams to hundreds of tons. In-house capabilities also include wet chemistry uranium processing, advanced heat treatment to optimize component material properties and a controlled, clean-room environment with the capacity to assemble railcar-size components. Fuel for the naval nuclear reactors is provided by Nuclear Fuel Services, Inc. (“NFS”), one of our wholly owned subsidiaries. Located in Erwin, NFS also converts Cold War-era government stockpiles of highly enriched uranium into material suitable for further processing into commercial nuclear reactor fuel.
		•		Our Technical Services segment provides various services to the U.S. Government, including uranium processing, environmental site restoration services and management and operating services for various U.S. Government-owned facilities. These services are provided to the Department of Defense and the DOE, including the NNSA, the Office of Nuclear Energy, the Office of Science, and the Office of Environmental Management. Through this segment we deliver products and management solutions to nuclear operations and high-consequence manufacturing facilities. A significant portion of this segment’s operations are conducted through joint ventures.
		•		Our Nuclear Energy segment supplies commercial nuclear steam generators and components to nuclear utility customers. B&W has supplied the nuclear industry with more than 1,300 large, heavy components worldwide. This segment is the only heavy nuclear component, N-Stamp certified manufacturer in North America. Our Nuclear Energy segment fabricates pressure vessels, reactors, steam generators, heat exchangers and other auxiliary equipment. This segment also provides specialized engineering services that include structural component design, 3-D thermal-hydraulic engineering analysis, weld and robotic process development and metallurgy and materials engineering. In addition, this segment offers services for nuclear steam generators and balance of plant equipment, as well as nondestructive examination and tooling/repair solutions for other plant systems and components. This segment also offers engineering and licensing services for new nuclear plant designs.
		•		Our mPower segment is designing the B&W mPower™ reactor, a small modular reactor (“SMR”) design generally based on proven light-water nuclear technology. Through our majority-owned joint venture, Generation mPower LLC (“GmP”), we are developing the associated mPower Plant power generating facility, which will use two B&W mPower™ reactors to generate greater than 360 MW within an advanced passively safe and secure plant architecture. As part of this initiative, we were selected to receive funding pursuant to a Cooperative Agreement with the DOE under its Small Modular Reactor Licensing Technical Support Program (the “Funding Program”) for SMR deployment. This Funding Program provided financial assistance for our mPower Plant licensing and engineering development costs associated with SMR design certification and generic design activities. On April 14, 2014, we announced our plans to restructure the mPower program to reduce spending and focus on technology development. Beginning in the third quarter of 2014, we slowed the pace of development and intend to invest no more than $15 million on an annual basis while we continue to search for additional investors in the mPower program. We intend to continue working with the DOE to further the program. At this time, the latest extension to the Cooperative Agreement has expired and the DOE funding has been suspended. If a mutually agreeable plan is not identified, future amounts may not be made available to us under the Funding Program.
	For financial information about our segments, see Note 16 to our consolidated financial statements included in this report.
Spin-off	Spin-off
	On November 5, 2014, we announced plans to separate our Power Generation business from our Government & Nuclear Operations business, which includes the Nuclear Operations, Technical Services, Nuclear Energy and mPower segments, through a spin-off, creating a new independent, publicly traded company, Babcock & Wilcox Enterprises, Inc. (“BW”). We expect the spin-off will be effective by mid-summer 2015, subject to several customary conditions, including final approval of the transaction by our Board of Directors. Concurrent with the spin-off, the Company will change its name to BWX Technologies, Inc. (“BWXT”). We plan to effect the separation through a tax-free spin-off transaction.
Use of Estimates	Use of Estimates
	We use estimates and assumptions to prepare our financial statements in conformity with GAAP. Some of our more significant estimates include our estimate of costs to complete long-term construction contracts, estimates of costs to be incurred to satisfy contractual warranty requirements, estimates of the value of acquired intangible assets and estimates we make in selecting assumptions related to the valuations of our pension and postretirement plans, including the selection of our discount rates, mortality and expected rates of return on our pension plan assets. These estimates and assumptions affect the amounts we report in our financial statements and accompanying notes. Our actual results could differ from these estimates. Variances could result in a material effect on our financial condition and results of operations in future periods.
Earnings Per Share	Earnings Per Share
	We have computed earnings per common share on the basis of the weighted average number of common shares, and, where dilutive, common share equivalents, outstanding during the indicated periods. We have a number of forms of stock-based compensation, including incentive and non-qualified stock options, restricted stock, restricted stock units and performance shares and performance units, subject to satisfaction of specific performance goals. We include the shares applicable to these plans in dilutive earnings per share when related performance criteria have been met.
Investments	Investments
	Our investment portfolio consists primarily of highly liquid money market instruments. Additionally, we currently hold Centrus Energy Corp. bonds and equities received upon USEC Inc.’s emergence from bankruptcy. Our investments are carried at fair value and are either classified as trading, with unrealized gains and losses reported in earnings, or as available-for-sale, with the unrealized gains and losses, net of tax, reported as a component of accumulated other comprehensive income. We classify investments available for current operations in the consolidated balance sheets as current assets, while we classify investments held for long-term purposes as noncurrent assets. We adjust the amortized cost of debt securities for amortization of premiums and accretion of discounts to maturity. That amortization is included in interest income. We include realized gains and losses on our investments in other – net. The cost of securities sold is based on the specific identification method. We include interest on securities in interest income.
Foreign Currency Translation	Foreign Currency Translation
	We translate assets and liabilities of our foreign operations into U.S. dollars at current exchange rates, and we translate income statement items at average exchange rates for the periods presented. We record adjustments resulting from the translation of foreign currency financial statements as a component of accumulated other comprehensive income. We report foreign currency transaction gains and losses in income. We have included in other - net transaction gains (losses) of $1.9 million, $0.5 million and $(0.6) million for the years ended December 31, 2014, 2013 and 2012, respectively.
Contracts and Revenue Recognition	Contracts and Revenue Recognition
	We generally recognize contract revenues and related costs on a percentage-of-completion method for individual contracts or combinations of contracts based on work performed, man hours or a cost-to-cost method, as applicable to the product or activity involved. We recognize estimated contract revenue and resulting income based on the measurement of the extent of progress completion as a percentage of the total project. Certain costs may be excluded from the cost-to-cost method of measuring progress, such as significant costs for materials and major third-party subcontractors, if it appears that such exclusion would result in a more meaningful measurement of actual contract progress and resulting periodic allocation of income. We include revenues and related costs so recorded, plus accumulated contract costs that exceed amounts invoiced to customers under the terms of the contracts, in contracts in progress. We include in advance billings on contracts billings that exceed accumulated contract costs and revenues and costs recognized under the percentage-of-completion method. Most long-term contracts contain provisions for progress payments. Our unbilled receivables do not contain an allowance for credit losses as we expect to invoice customers and collect all amounts for unbilled revenues. We review contract price and cost estimates periodically as the work progresses and reflect adjustments proportionate to the percentage-of-completion in income in the period when those estimates are revised. For all contracts, if a current estimate of total contract cost indicates a loss on a contract, the projected loss is recognized in full when determined.
	For contracts as to which we are unable to estimate the final profitability except to assure that no loss will ultimately be incurred, we recognize equal amounts of revenue and cost until the final results can be estimated more precisely. For these deferred profit recognition contracts, we recognize revenue and cost equally and only recognize gross margin when probable and reasonably estimable, which we generally determine to be when the contract is approximately 70% complete. We treat long-term construction contracts that contain such a level of risk and uncertainty that estimation of the final outcome is impractical, except to assure that no loss will be incurred, as deferred profit recognition contracts.
	Our policy is to account for fixed-price contracts under the completed-contract method if we believe that we are unable to reasonably forecast cost to complete at start-up. Under the completed-contract method, income is recognized only when a contract is completed or substantially complete.
	For parts orders and certain aftermarket services activities, we recognize revenues as goods are delivered and work is performed.
	Variations from estimated contract performance could result in material adjustments to operating results for any fiscal quarter or year. We include claims for extra work or changes in scope of work to the extent of costs incurred in contract revenues when we believe collection is probable. In the year ended December 31, 2014, we executed a change order in our Nuclear Operations segment that increased the value of existing contracts by $70.5 million. We recognized $46.4 million of revenue for the cumulative effect of this contract change, as well as $25.8 million in cost of operations for the recognition of the associated costs being recovered.
	In the year ended December 31, 2014, we recorded a contract loss totaling approximately $11.6 million for additional estimated costs to complete our Power Generation segment’s Berlin Station project. These losses are in addition to contract losses recorded on this project of $35.6 million and $16.9 million in 2013 and 2012, respectively. We previously asserted that substantial completion had been achieved on this project in early 2014 and that any further delays to complete this project were the result of the customer’s failure to supply fuel complying with the contract specifications. The customer certified that we achieved substantial completion on the project effective July 19, 2014, following which we believe the customer has no further claims for liquidated damages associated with the delays. See Note 10 for legal proceedings associated with this matter.
	The following represent the components of our contracts in progress and advance billings on contracts included in our consolidated balance sheets:
			December 31,
			2014			2013
			(In thousands)
	Included in Contracts in Progress:
	Costs incurred less costs of revenue recognized		$	183,312		$	150,724
	Revenues recognized less billings to customers			215,061			220,096
	Contracts In Progress		$	398,373		$	370,820
	Included In Advance Billings on Contracts:
	Billings to customers less revenues recognized		$	274,151		$	411,156
	Costs incurred less costs of revenue recognized			(18,616	)		(93,385	)
	Advance Billings on Contracts		$	255,535		$	317,771
	The following amounts represent retainages on contracts:
			December 31,
			2014			2013
			(In thousands)
	Retainages expected to be collected within one year		$	103,867		$	84,389
	Retainages expected to be collected after one year			9,092			12,820
	Total retainages		$	112,959		$	97,209
	We have included retainages expected to be collected in 2015 in accounts receivable – trade, net. Retainages expected to be collected after one year are included in other assets. Of the long-term retainages at December 31, 2014, we anticipate collecting $1.8 million in 2016, $5.9 million in 2017 and $1.4 million in 2018.
Comprehensive Income	Comprehensive Income
	The components of accumulated other comprehensive income included in stockholders’ equity are as follows:
			December 31,
			2014			2013
			(In thousands)
	Currency translation adjustments		$	11,547		$	38,415
	Net unrealized gain on available-for-sale investments			155			130
	Net unrealized gain (loss) on derivative financial instruments			(123	)		627
	Unrecognized prior service cost on benefit obligations			(7,983	)		(10,824	)
	Accumulated other comprehensive income		$	3,596		$	28,348
	The amounts reclassified out of accumulated other comprehensive income by component and the affected consolidated statements of income line items are as follows:
			Year ended December 31,
			2014			2013			2012
	Accumulated Other Comprehensive Income		(In thousands)									Line Item Presented
	Component Recognized
	Realized (loss) gain on derivative financial instruments		$	620		$	(1,885	)	$	(1,082	)	Revenues
				(2,793	)		(2,174	)		3,833		Cost of operations
				4			144			(24	)	Other-net
				(2,169	)		(3,915	)		2,727		Total before tax
				559			973			(704	)	Provision for Income Taxes
			$	(1,610	)	$	(2,942	)	$	2,023		Net Income
	Amortization of prior service cost on benefit obligations		$	(3,433	)	$	(2,813	)	$	(3,271	)	Cost of operations
				(1,795	)		(197	)		(169	)	Selling, general and administrative expenses
				(5,228	)		(3,010	)		(3,440	)	Total before tax
				1,547			1,035			1,159		Provision for Income Taxes
			$	(3,681	)	$	(1,975	)	$	(2,281	)	Net Income
	Realized gains on investments		$	172		$	799		$	35		Other-net
				(61	)		(30	)		—		Provision for Income Taxes
			$	111		$	769		$	35		Net Income
	Total reclassification for the period		$	(5,180	)	$	(4,148	)	$	(223	)
Warranty Expense	Warranty Expense
	We accrue estimated expense included in cost of operations on our consolidated statements of income to satisfy contractual warranty requirements when we recognize the associated revenue on the related contracts. In addition, we record specific provisions or reductions where we expect the actual warranty costs to significantly differ from the accrued estimates. Such changes could have a material effect on our consolidated financial condition, results of operations and cash flows.
	The following summarizes the changes in the carrying amount of accrued warranty expense:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	56,436		$	83,682		$	97,209
	Additions			14,993			18,486			20,972
	Acquisition of MEGTEC			4,693			—			—
	Expirations and other changes			(6,393	)		(24,801	)		(24,766	)
	Payments			(14,807	)		(20,250	)		(10,217	)
	Translation and other			(1,298	)		(681	)		484
	Balance at end of period		$	53,624		$	56,436		$	83,682
Asset Retirement Obligations and Environmental Clean-up Costs	Asset Retirement Obligations and Environmental Clean-up Costs
	We accrue for future decommissioning of our nuclear facilities that will permit the release of these facilities to unrestricted use at the end of each facility’s life, which is a requirement of our licenses from the NRC. In accordance with the FASB Topic Asset Retirement and Environmental Obligations, we record the fair value of a liability for an asset retirement obligation in the period in which it is incurred. When we initially record such a liability, we capitalize a cost by increasing the carrying amount of the related long-lived asset. Over time, the liability is accreted to its present value each period and the capitalized cost is depreciated over the useful life of the related asset. Upon settlement of a liability, we will settle the obligation for its recorded amount or incur a gain or loss. This topic applies to environmental liabilities associated with assets that we currently operate and are obligated to remove from service. For environmental liabilities associated with assets that we no longer operate, we have accrued amounts based on the estimated costs of clean-up activities for which we are responsible, net of any cost-sharing arrangements. We adjust the estimated costs as further information develops or circumstances change. An exception to this accounting treatment relates to the work we perform for two facilities for which the U.S. Government is obligated to pay substantially all of the decommissioning costs.
	Substantially all of our asset retirement obligations relate to the remediation of our nuclear analytical laboratory and the NFS facility in our Nuclear Operations segment. The following table reflects our asset retirement obligations:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	44,771		$	42,366		$	35,885
	Costs incurred			—			—			—
	Additions/Adjustments			418			(109	)		3,422
	Accretion			2,622			2,514			3,059
	Balance at end of period		$	47,811		$	44,771		$	42,366
Research and Development	Research and Development
	Our research and development activities are related to the development and improvement of new and existing products and equipment, as well as conceptual and engineering evaluation for translation into practical applications. We charge the costs of research and development unrelated to specific contracts as incurred. Substantially all of these costs are in our Power Generation and mPower segments, the majority of which are related to the development of our B&W mPower™ reactor and the associated mPower Plant. Contractual arrangements for customer-sponsored research and development can vary on a case-by-case basis and include contracts, cooperative agreements and grants. Research and development activities totaled $142.8 million, $200.8 million and $173.9 million in the years ended December 31, 2014, 2013 and 2012, respectively. This includes amounts paid for by our customers of $41.8 million, $43.2 million and $53.4 million, in the years ended December 31, 2014, 2013 and 2012, respectively, and DOE funds provided under the Funding Program of $27.8 million and $78.4 million in the years ended December 31, 2014 and 2013, respectively. Amounts provided under the Funding Program in the year ended December 31, 2013 include $21.5 million of pre-award cost reimbursement, $9.7 million of which related to research and development costs incurred in the year ended December 31, 2012.
	During the years ended December 31, 2014, 2013 and 2012, we recognized $5.8 million, $15.8 million and $17.9 million, respectively, of non-cash in-kind research and development costs (included above) related to services contributed by our minority partner to GmP, our majority-owned subsidiary formed in 2011 to oversee the program to develop the small modular nuclear power plant based on B&W mPower™ technology.
Pension Plans and Postretirement Benefits	Pension Plans and Postretirement Benefits
	We sponsor various defined benefit pension and postretirement plans covering certain employees of our U.S. and international subsidiaries. We utilize actuarial valuations to calculate the cost and benefit obligations of our pension and postretirement benefits. The actuarial valuations utilize significant assumptions in the determination of our benefit cost and obligations, including assumptions regarding discount rates, expected returns on plan assets, mortality and health care cost trends. We determine our discount rate based on a review of published financial data and discussions with our actuary regarding rates of return on high-quality, fixed-income investments currently available and expected to be available during the period to maturity of our pension and postretirement plan obligations. The expected rate of return on plan assets assumption is based on capital market assumptions of the long-term expected returns for the investment mix of assets currently in the portfolio. The expected rate of return on plan assets is determined to be the weighted average of the nominal returns based on the weightings of the classes within the total asset portfolio. Expected health care cost trends represent expected annual rates of change in the cost of health care benefits and are estimated based on analysis of health care cost inflation. For the year ended December 31, 2014, we adjusted the mortality assumption for our domestic plans to reflect mortality improvements identified by the Society of Actuaries, adjusted for the Company’s experience.
	The components of benefit cost related to service cost, interest cost, expected return on plan assets and prior service cost amortization are recorded on a quarterly basis based on actuarial assumptions. In the fourth quarter of each year, or as interim remeasurements are required, we immediately recognize net actuarial gains and losses into earnings as a component of net periodic benefit cost. Recognized net actuarial gains and losses consist primarily of our reported actuarial gains and losses and the difference between the actual return on plan assets and the expected return on plan assets.
	We recognize the funded status of each plan as either an asset or a liability in the consolidated balance sheets. The funded status is the difference between the fair value of plan assets and the present value of its benefit obligation, determined on a plan-by-plan basis. Our pension plan assets can include assets that are difficult to value. See Note 7 for a detailed description of our plan assets.
Income Taxes	Income Taxes
	Income tax expense for federal, foreign, state and local income taxes are calculated on pre-tax income based on current tax law and includes the cumulative effect of any changes in tax rates from those used previously in determining deferred tax assets and liabilities. We record a valuation allowance to reduce our deferred tax assets to the amount that is more likely than not to be realized. We assess deferred taxes and the adequacy of the valuation allowance on a quarterly basis. In the ordinary course of business there is inherent uncertainty in quantifying our income tax positions. We assess our income tax positions and record tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, we have recorded the largest amount of tax benefit with a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is not more likely than not that a tax benefit will be sustained, no tax benefit has been recognized in the financial statements. We record interest and penalties (net of any applicable tax benefit) related to income taxes as a component of provision for income taxes on our consolidated statements of income.
Inventories	Inventories
	We carry our inventories at the lower of cost or market. We determine cost principally on the first-in, first-out basis, except for certain materials inventories of our Power Generation segment, for which we use the last-in, first-out (“LIFO”) method. We determined the cost of approximately 17% and 18% of our total inventories using the LIFO method at December 31, 2014 and 2013, respectively, and our total LIFO reserve at December 31, 2014 and 2013 was approximately $7.9 million and $7.7 million, respectively. Inventories are summarized below:
			December 31,
			2014			2013
			(In thousands)
	Raw Materials and Supplies		$	81,530		$	85,455
	Work in Progress			9,831			10,872
	Finished Goods			17,276			16,731
	Total Inventories		$	108,637		$	113,058
Property, Plant and Equipment	Property, Plant and Equipment
	We carry our property, plant and equipment at depreciated cost, less any impairment provisions. We depreciate our property, plant and equipment using the straight-line method over estimated economic useful lives of eight to 33 years for buildings and three to 28 years for machinery and equipment. Our depreciation expense was $92.9 million, $62.2 million and $59.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. We expense the costs of maintenance, repairs and renewals that do not materially prolong the useful life of an asset as we incur them.
	Property, plant and equipment is stated at cost and is set forth below:
			December 31,
			2014			2013
			(In thousands)
	Land		$	15,506		$	11,718
	Buildings			253,338			249,614
	Machinery and equipment			827,029			782,633
	Property under construction			71,708			82,718
				1,167,581			1,126,683
	Less accumulated depreciation			730,946			679,604
	Net Property, Plant and Equipment		$	436,635		$	447,079
Investments in Unconsolidated Affiliates	Investments in Unconsolidated Affiliates
	We use the equity method of accounting for affiliates in which we are able to exert significant influence. Currently, substantially all of our material investments in affiliates that are not consolidated are recorded using the equity method. Affiliates in which our investment ownership is less than 20% and where we are unable to exert significant influence are carried at cost.
Goodwill	Goodwill
	Goodwill represents the excess of the cost of our acquired businesses over the fair value of the net assets acquired. We perform testing of goodwill for impairment annually. We may elect to perform a qualitative test when we believe that there is sufficient excess fair value over carrying value based on our most recent quantitative assessment, adjusted for relevant events and circumstances that could affect fair value during the current year. If we conclude based on this assessment that it is more likely than not that the reporting unit is not impaired, we do not perform a quantitative impairment test. In all other circumstances, we utilize a two-step quantitative impairment test to identify potential goodwill impairment and measure the amount of any goodwill impairment. The first step of the test compares the fair value of a reporting unit with its carrying amount, including goodwill. If the carrying amount of a reporting unit exceeds its fair value, the second step of the goodwill impairment test is performed to measure the amount of the impairment loss, if any. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill.
	The following summarizes the changes in the carrying amount of goodwill:
			Power			Nuclear			Technical			Nuclear		Total
			Generation			Operations			Services			Energy
			(In thousands)
	Balance at December 31, 2012		$	103,702		$	118,103		$	45,000		$	13,975	$	280,780
	Currency translation adjustments and other			928			—			—			—		928
	Balance at December 31, 2013		$	104,630		$	118,103		$	45,000		$	13,975	$	281,708
	Purchase price adjustment for acquisition of MEGTEC (Note 2)			108,800			—			—			—		108,800
	Currency translation adjustments and other(1)			(4,152	)		(7,164	)		—			—		(11,316	)
	Balance at December 31, 2014		$	209,278		$	110,939		$	45,000		$	13,975	$	379,192
	-1	Includes adjustments resulting from acquisitions occurring prior to December 31, 2012 of $(7.2) million and changes from foreign currency translation adjustments of $(4.2) million and $0.9 million for the years ended December 31, 2013 and 2012, respectively.
Intangible Assets	Intangible Assets
	Intangible assets are recognized at fair value when acquired. Intangible assets with definite lives are amortized to operating expense using the straight-line method over their estimated useful lives and tested for impairment when events or changes in circumstances indicate that their carrying amounts may not be recoverable. Intangible assets with indefinite lives are not amortized and are subject to annual impairment testing. We may elect to perform a qualitative assessment when testing indefinite lived intangible assets for impairment to determine whether events or circumstances affecting significant inputs related to the most recent quantitative evaluation have occurred, indicating that it is more likely than not that the indefinite lived intangible asset is impaired. Otherwise, we test indefinite lived intangible assets for impairment by quantitatively determining the fair value of the indefinite lived intangible asset and comparing the fair value of the intangible asset to its carrying amount. If the carrying amount of the intangible asset exceeds its fair value, we recognize impairment for the amount of the difference. Our intangible assets are as follows:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Amortized intangible assets:
	Gross cost:
	Customer relationships		$	57,539		$	35,383		$	36,644
	Acquired backlog			10,600			—			2,979
	Tradename			11,457			11,945			11,945
	Unpatented technology			8,472			6,422			6,422
	Patented technology			2,521			2,521			6,961
	All other			9,765			9,755			7,912
	Total		$	100,354		$	66,026		$	72,863
	Accumulated amortization:
	Customer relationships		$	(17,011	)	$	(13,490	)	$	(11,173	)
	Acquired backlog			(5,300	)		—			(1,457	)
	Tradename			(2,959	)		(8,015	)		(6,422	)
	Unpatented technology			(3,442	)		(3,335	)		(2,682	)
	Patented technology			(1,122	)		(806	)		(4,235	)
	All other			(4,782	)		(3,994	)		(4,343	)
	Total		$	(34,616	)	$	(29,640	)	$	(30,312	)
	Net amortized intangible assets		$	65,738		$	36,386		$	42,551
	Unamortized intangible assets:
	NRC category 1 license		$	43,830		$	43,830		$	43,830
	Trademarks and trade names			1,305			1,305			1,305
	Total unamortized intangible assets		$	45,135		$	45,135		$	45,135
	The following summarizes the changes in the carrying amount of intangible assets:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	81,521		$	87,686		$	103,041
	Business acquisitions and adjustments			44,972			2,200			(1,746	)
	Amortization expense			(12,923	)		(8,324	)		(11,010	)
	Impairment charge			(1,730	)		(1,260	)		(3,216	)
	Currency translation adjustments and other			(967	)		1,219			617
	Balance at end of period		$	110,873		$	81,521		$	87,686
	We recognized impairment charges totaling $1.7 million and $1.3 million in the years ended December 31, 2014 and 2013, respectively, related to the cancellation of operations and maintenance services contracts and the sale of a subsidiary in our Power Generation segment.
	Estimated amortization expense for the next five fiscal years is as follows (in thousands):
	Year Ending December 31,		Amount
	2015		$	13,360
	2016		$	8,006
	2017		$	7,912
	2018		$	7,262
	2019		$	6,908
Other Non-Current Assets	Other Non-Current Assets
	We have included deferred debt issuance costs in other assets. We amortize deferred debt issuance costs as interest expense over the life of the related debt. The following summarizes the changes in the carrying amount of these assets:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	6,518		$	8,468		$	5,723
	Additions			5,473			—			4,902
	Interest expense – debt issuance costs			(2,070	)		(1,950	)		(2,157	)
	Balance at end of period		$	9,921		$	6,518		$	8,468
Capitalization of Interest Cost	Capitalization of Interest Cost
	We capitalize interest in accordance with FASB Topic Interest. We incurred total interest of $9.2 million, $4.8 million and $4.9 million in the years ended December 31, 2014, 2013 and 2012, respectively, of which we capitalized $1.9 million, $1.7 million and $1.2 million in the years ended December 31, 2014, 2013 and 2012, respectively.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash
	Our cash equivalents are highly liquid investments, with maturities of three months or less when we purchase them.
	We record cash and cash equivalents as restricted when we are unable to freely use such cash and cash equivalents for our general operating purposes. At December 31, 2014, we had restricted cash and cash equivalents totaling $57.2 million, $3.7 million of which was held in restricted foreign cash accounts, $2.7 million of which was held for future decommissioning of facilities (which is included in other assets on our consolidated balance sheets), and $50.8 million of which was held to meet reinsurance reserve requirements of our captive insurer.
Derivative Financial Instruments	Derivative Financial Instruments
	Our global operations give rise to exposure to market risks from changes in foreign currency exchange (“FX”) rates. We use derivative financial instruments, primarily FX forward contracts, to reduce the impact of changes in FX rates on our operating results. We use these instruments primarily to hedge our exposure associated with revenues or costs on our long-term contracts that are denominated in currencies other than our operating entities’ functional currencies. We do not hold or issue derivative financial instruments for trading or other speculative purposes.
	We enter into derivative financial instruments primarily as hedges of certain firm purchase and sale commitments denominated in foreign currencies. We record these contracts at fair value on our consolidated balance sheets and defer the related gains and losses in stockholders’ equity as a component of accumulated other comprehensive income until the hedged item is recognized in earnings. Any ineffective portion of a derivative’s change in fair value and any portion excluded from the assessment of effectiveness is immediately recognized in other – net on our consolidated statements of income. The gain or loss on a derivative instrument not designated as a hedging instrument is also immediately recognized in earnings. Gains and losses on derivative financial instruments that require immediate recognition are included as a component of other – net in our consolidated statements of income.
Self Insurance	Self-Insurance
	We have a wholly owned insurance subsidiary that provides employer’s liability, general and automotive liability and workers’ compensation insurance and, from time to time, builder’s risk insurance (within certain limits) to our companies. We may also, in the future, have this insurance subsidiary accept other risks that we cannot or do not wish to transfer to outside insurance companies. Included in other liabilities on our consolidated balance sheets are reserves for self-insurance totaling $32.8 million and $37.8 million at December 31, 2014 and 2013, respectively. The reduction in 2014 was primarily attributable to a change in estimate based on historical loss experience recognized in cost of operations in our consolidated statements of income.
Loss Contingencies	Loss Contingencies
	We estimate liabilities for loss contingencies when it is probable that a liability has been incurred and the amount of loss is reasonably estimable. We provide disclosure when there is a reasonable possibility that the ultimate loss will exceed the recorded provision or if such probable loss is not reasonably estimable. We are currently involved in some significant litigation, as discussed in Note 10. Our losses are typically resolved over long periods of time and are often difficult to assess and estimate due to, among other reasons, the possibility of multiple actions by third parties; the attribution of damages, if any, among multiple defendants; plaintiffs, in most cases involving personal injury claims, do not specify the amount of damages claimed; the discovery process may take multiple years to complete; during the litigation process, it is common to have multiple complex unresolved procedural and substantive issues; the potential availability of insurance and indemnity coverages; the wide-ranging outcomes reached in similar cases, including the variety of damages awarded; the likelihood of settlements for de minimus amounts prior to trial; the likelihood of success at trial; and the likelihood of success on appeal. Consequently, it is possible future earnings could be affected by changes in our assessments of the probability that a loss has been incurred in a material pending litigation against us and/or changes in our estimates related to such matters.
Stock-Based Compensation	Stock-Based Compensation
	We expense stock-based compensation in accordance with FASB Topic Compensation – Stock Compensation. Under this topic, the fair value of equity-classified awards, such as restricted stock, performance shares and stock options, is determined on the date of grant and is not remeasured. The fair value of liability-classified awards, such as cash-settled stock appreciation rights, restricted stock units and performance units, is determined on the date of grant and is remeasured at the end of each reporting period through the date of settlement. Grant date fair values for restricted stock, restricted stock units, performance shares and performance units are determined using the closing price of our common stock on the date of grant. Grant date fair values for stock options and stock appreciation rights are determined using a Black-Scholes option-pricing model (“Black-Scholes”). For performance shares or units granted in the year ended December 31, 2014 that contain a Relative Total Shareholder Return vesting criteria, we utilize a Monte Carlo simulation to determine the grant date fair value, which determines the probability of satisfying the market condition included in the award. The determination of the fair value of a share-based payment award using an option-pricing model requires the input of significant assumptions, such as the expected life of the award and stock price volatility.
	Under the provisions of this FASB topic, we recognize expense, net of an estimated forfeiture rate, for all share-based awards granted on a straight-line basis over the requisite service periods of the awards, which is generally equivalent to the vesting term. This topic requires compensation expense to be recognized, net of an estimate for forfeitures, such that compensation expense is recorded only for those awards expected to vest. We review the estimate for forfeitures periodically and record any adjustments deemed necessary for each reporting period. If our actual forfeiture rate is materially different from our estimate, the stock-based compensation expense could be significantly different from what we have recorded in the current period.
	Additionally, this FASB topic amended FASB Topic Statement of Cash Flows, to require excess tax benefits to be reported as a financing cash flow, rather than as a reduction of taxes paid. These excess tax benefits result from tax deductions in excess of the cumulative compensation expense recognized for options exercised and other equity-classified awards.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards
	In February 2013, the FASB issued an update to the Topic Liabilities. This update requires an entity to recognize obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. On January 1, 2014, we adopted this update. The adoption of these provisions did not have an impact on our financial statements.
	In July 2013, the FASB issued an update to the Topic Income Taxes. This update relates to the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, similar tax loss, or tax credit carryforward exists. On January 1, 2014, we adopted this update. The adoption of these provisions did not have an impact on our financial statements.
	In April 2014, the FASB issued an update to the Topics Presentation of Financial Statements and Property, Plant and Equipment. This update changes the criteria for reporting discontinued operations such that a disposal of a component of an entity will be required to be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results. We early adopted this pronouncement in the second quarter of 2014. The disposal of our Nuclear Projects business in the second quarter of 2014 did not qualify as a discontinued operation under the new guidance due to its relative insignificance to B&W’s operations and financial results. See Note 2 for additional information related to this disposal.
New Accounting Standards	New Accounting Standards
	In May 2014, the FASB issued Revenue from Contracts with Customers, which supersedes the revenue recognition requirements in the Topic Revenue Recognition and most industry specific guidance. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. This update is effective in 2017 and early adoption is not permitted. The update may be adopted either retrospectively to each prior period or as a cumulative-effect adjustment on the date of adoption. We are currently evaluating the impact of the adoption of this standard on our financial statements.
	In August 2014, the FASB issued an update to the Topic Presentation of Financial Statements. This update requires an entity to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. If there is substantial doubt about an entity’s ability to continue as a going concern, certain disclosures are required. This update will be effective for us in 2017. We do not expect the adoption of this update to have a material impact on our financial statements.

Basis_of_Presentation_and_Sign2

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Contracts in Progress and Advance Billings	The following represent the components of our contracts in progress and advance billings on contracts included in our consolidated balance sheets:
			December 31,
			2014			2013
			(In thousands)
	Included in Contracts in Progress:
	Costs incurred less costs of revenue recognized		$	183,312		$	150,724
	Revenues recognized less billings to customers			215,061			220,096
	Contracts In Progress		$	398,373		$	370,820
	Included In Advance Billings on Contracts:
	Billings to customers less revenues recognized		$	274,151		$	411,156
	Costs incurred less costs of revenue recognized			(18,616	)		(93,385	)
	Advance Billings on Contracts		$	255,535		$	317,771
Retainages on Contracts	The following amounts represent retainages on contracts:
			December 31,
			2014			2013
			(In thousands)
	Retainages expected to be collected within one year		$	103,867		$	84,389
	Retainages expected to be collected after one year			9,092			12,820
	Total retainages		$	112,959		$	97,209
Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income included in stockholders’ equity are as follows:
			December 31,
			2014			2013
			(In thousands)
	Currency translation adjustments		$	11,547		$	38,415
	Net unrealized gain on available-for-sale investments			155			130
	Net unrealized gain (loss) on derivative financial instruments			(123	)		627
	Unrecognized prior service cost on benefit obligations			(7,983	)		(10,824	)
	Accumulated other comprehensive income		$	3,596		$	28,348
Schedule of Amounts Reclassified from Accumulated Other Comprehensive Income	The amounts reclassified out of accumulated other comprehensive income by component and the affected consolidated statements of income line items are as follows:
			Year ended December 31,
			2014			2013			2012
	Accumulated Other Comprehensive Income		(In thousands)									Line Item Presented
	Component Recognized
	Realized (loss) gain on derivative financial instruments		$	620		$	(1,885	)	$	(1,082	)	Revenues
				(2,793	)		(2,174	)		3,833		Cost of operations
				4			144			(24	)	Other-net
				(2,169	)		(3,915	)		2,727		Total before tax
				559			973			(704	)	Provision for Income Taxes
			$	(1,610	)	$	(2,942	)	$	2,023		Net Income
	Amortization of prior service cost on benefit obligations		$	(3,433	)	$	(2,813	)	$	(3,271	)	Cost of operations
				(1,795	)		(197	)		(169	)	Selling, general and administrative expenses
				(5,228	)		(3,010	)		(3,440	)	Total before tax
				1,547			1,035			1,159		Provision for Income Taxes
			$	(3,681	)	$	(1,975	)	$	(2,281	)	Net Income
	Realized gains on investments		$	172		$	799		$	35		Other-net
				(61	)		(30	)		—		Provision for Income Taxes
			$	111		$	769		$	35		Net Income
	Total reclassification for the period		$	(5,180	)	$	(4,148	)	$	(223	)
Summary of Changes in Carrying Amount of Accrued Warranty Expense	The following summarizes the changes in the carrying amount of accrued warranty expense:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	56,436		$	83,682		$	97,209
	Additions			14,993			18,486			20,972
	Acquisition of MEGTEC			4,693			—			—
	Expirations and other changes			(6,393	)		(24,801	)		(24,766	)
	Payments			(14,807	)		(20,250	)		(10,217	)
	Translation and other			(1,298	)		(681	)		484
	Balance at end of period		$	53,624		$	56,436		$	83,682
Asset Retirement Obligations	The following table reflects our asset retirement obligations:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	44,771		$	42,366		$	35,885
	Costs incurred			—			—			—
	Additions/Adjustments			418			(109	)		3,422
	Accretion			2,622			2,514			3,059
	Balance at end of period		$	47,811		$	44,771		$	42,366
Inventories	Inventories are summarized below:
			December 31,
			2014			2013
			(In thousands)
	Raw Materials and Supplies		$	81,530		$	85,455
	Work in Progress			9,831			10,872
	Finished Goods			17,276			16,731
	Total Inventories		$	108,637		$	113,058
Property, Plant and Equipment	Property, plant and equipment is stated at cost and is set forth below:
			December 31,
			2014			2013
			(In thousands)
	Land		$	15,506		$	11,718
	Buildings			253,338			249,614
	Machinery and equipment			827,029			782,633
	Property under construction			71,708			82,718
				1,167,581			1,126,683
	Less accumulated depreciation			730,946			679,604
	Net Property, Plant and Equipment		$	436,635		$	447,079
Changes in Carrying Amount of Goodwill	The following summarizes the changes in the carrying amount of goodwill:
			Power			Nuclear			Technical			Nuclear		Total
			Generation			Operations			Services			Energy
			(In thousands)
	Balance at December 31, 2012		$	103,702		$	118,103		$	45,000		$	13,975	$	280,780
	Currency translation adjustments and other			928			—			—			—		928
	Balance at December 31, 2013		$	104,630		$	118,103		$	45,000		$	13,975	$	281,708
	Purchase price adjustment for acquisition of MEGTEC (Note 2)			108,800			—			—			—		108,800
	Currency translation adjustments and other(1)			(4,152	)		(7,164	)		—			—		(11,316	)
	Balance at December 31, 2014		$	209,278		$	110,939		$	45,000		$	13,975	$	379,192
	-1	Includes adjustments resulting from acquisitions occurring prior to December 31, 2012 of $(7.2) million and changes from foreign currency translation adjustments of $(4.2) million and $0.9 million for the years ended December 31, 2013 and 2012, respectively.
Schedule of Intangible Assets	Our intangible assets are as follows:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Amortized intangible assets:
	Gross cost:
	Customer relationships		$	57,539		$	35,383		$	36,644
	Acquired backlog			10,600			—			2,979
	Tradename			11,457			11,945			11,945
	Unpatented technology			8,472			6,422			6,422
	Patented technology			2,521			2,521			6,961
	All other			9,765			9,755			7,912
	Total		$	100,354		$	66,026		$	72,863
	Accumulated amortization:
	Customer relationships		$	(17,011	)	$	(13,490	)	$	(11,173	)
	Acquired backlog			(5,300	)		—			(1,457	)
	Tradename			(2,959	)		(8,015	)		(6,422	)
	Unpatented technology			(3,442	)		(3,335	)		(2,682	)
	Patented technology			(1,122	)		(806	)		(4,235	)
	All other			(4,782	)		(3,994	)		(4,343	)
	Total		$	(34,616	)	$	(29,640	)	$	(30,312	)
	Net amortized intangible assets		$	65,738		$	36,386		$	42,551
	Unamortized intangible assets:
	NRC category 1 license		$	43,830		$	43,830		$	43,830
	Trademarks and trade names			1,305			1,305			1,305
	Total unamortized intangible assets		$	45,135		$	45,135		$	45,135
Changes in Carrying Amount of Intangible Assets	The following summarizes the changes in the carrying amount of intangible assets:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	81,521		$	87,686		$	103,041
	Business acquisitions and adjustments			44,972			2,200			(1,746	)
	Amortization expense			(12,923	)		(8,324	)		(11,010	)
	Impairment charge			(1,730	)		(1,260	)		(3,216	)
	Currency translation adjustments and other			(967	)		1,219			617
	Balance at end of period		$	110,873		$	81,521		$	87,686
Estimated Amortization Expense	Estimated amortization expense for the next five fiscal years is as follows (in thousands):
	Year Ending December 31,		Amount
	2015		$	13,360
	2016		$	8,006
	2017		$	7,912
	2018		$	7,262
	2019		$	6,908
Changes in Carrying Amount of Other Non-Current Assets	The following summarizes the changes in the carrying amount of these assets:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	Balance at beginning of period		$	6,518		$	8,468		$	5,723
	Additions			5,473			—			4,902
	Interest expense – debt issuance costs			(2,070	)		(1,950	)		(2,157	)
	Balance at end of period		$	9,921		$	6,518		$	8,468

Business_Acquisitions_and_Disp1

Business Acquisitions and Dispositions (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Summary of Purchase Price Allocation Including Finalization of Asset Valuations	Our preliminary purchase price allocation, as follows, is subject to change upon receipt of additional information and completion of further analysis, including, but not limited to, finalization of long-lived and intangible asset valuations:
		MEGTEC
		(in thousands)
	Cash and cash equivalents	$	14,232
	Accounts receivable		23,054
	Inventories		5,395
	Other current assets		9,200
	Property, plant and equipment		5,090
	Goodwill		108,800
	Intangible assets		44,250
	Total assets acquired	$	210,021
	Accounts payable		13,402
	Advance billings on contracts		11,144
	Other current liabilities		18,089
	Pension liability		5,041
	Deferred income taxes		5,202
	Other liabilities		130
	Total liabilities assumed	$	53,008
	Net assets acquired	$	157,013
	Cash and cash equivalents acquired		14,232
	Net assets acquired, net of unrestricted cash acquired	$	142,781
	Amount of tax deductible goodwill	$	34,583
Summary of Intangible Assets Acquired	The preliminary intangible assets included above consist of the following (dollar amounts in thousands):
		Amount		Amortization
				Period
	Customer relationships	$	24,400		7 years
	Backlog	$	10,600		1 year
	Trade names / trademarks	$	6,000		15 years
	Developed technology	$	3,250		10 years
Summary of Unaudited Pro Forma Financial Information	The unaudited pro forma financial information below is not intended to represent or be indicative of our actual consolidated results had we completed the acquisition at January 1, 2013. This information is presented for comparative purposes only and should not be taken as representative of our future consolidated results of operations.
		Year Ended
		December 31,
		2014		2013
	Revenues	$	3,003,351	$	3,445,597
	Net Income Attributable to The Babcock & Wilcox Company	$	36,357	$	341,774
	Basic Earnings per Common Share	$	0.34	$	3.05
	Diluted Earnings per Common Share	$	0.33	$	3.03

Equity_Method_Investments_Tabl

Equity Method Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Summary of Combined Balance Sheet Information	Summarized below is combined balance sheet and income statement information for investments accounted for under the equity method:
		December 31,
		2014			2013
		(In thousands)
	Current assets	$	706,845		$	800,704
	Noncurrent assets		181,517			252,430
	Total Assets	$	888,362		$	1,053,134
	Current liabilities	$	507,616		$	610,329
	Noncurrent liabilities		97,419			72,742
	Owners’ equity		283,327			370,063
	Total Liabilities and Owners’ Equity	$	888,362		$	1,053,134
Summary of Combined Income Statement Information
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Revenues	$	2,109,159		$	2,832,202		$	2,758,159
	Gross profit	$	157,472		$	208,714		$	210,425
	Income before provision for income taxes	$	95,013		$	150,511		$	146,911
	Provision for income taxes		6,160			8,603			9,000
	Net Income	$	88,853		$	141,908		$	137,911
Reconciliation of Net Income to Equity in Income	Reconciliation of net income per combined income statement information of our investees to equity in income of investees per our consolidated statements of income is as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Equity income based on stated ownership percentages	$	43,263		$	68,305		$	66,064
	All other adjustments due to amortization of basis differences, timing of GAAP adjustments and other adjustments		(1,507	)		(247	)		645
	Equity in income of investees	$	41,756		$	68,058		$	66,709
Schedule of Transactions with Unconsolidated Affiliates	Our transactions with unconsolidated affiliates were as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Sales to	$	87,722		$	99,443		$	42,538
	Purchases from	$	5,623		$	4,645		$	1,814
	Dividends received	$	60,519		$	79,595		$	51,594
	Capital contributions, net of returns	$	4,900		$	6,884		$	6,289

Special_Charges_for_Restructur1

Special Charges for Restructuring Activities (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Changes in Restructuring Liabilities
			Year Ended December 31,
			2014			2013
			(In thousands)
	Liability balance at the beginning of the period		$	10,054		$	—
	Special charges for restructuring activities(1)			30,298			36,150
	Payments			(30,321	)		(26,096	)
	Translation and other			(366	)		—
	Liability balance at the end of the period		$	9,665		$	10,054
	-1	Excludes non-cash charges of $10.8 million and $3.4 million for the years ended December 31, 2014 and 2013, respectively, which did not impact the restructuring liability.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Reconciliation of Unrecognized Tax Benefits	A reconciliation of unrecognized tax benefits follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Balance at beginning of period	$	5,730		$	4,487		$	32,357
	Increases based on tax positions taken in the current year		868			732			980
	Increases based on tax positions taken in the prior years		3,536			1,546			65
	Decreases based on tax positions taken in the prior years		(260	)		(167	)		(3,114	)
	Decreases due to settlements with tax authorities		(350	)		—			(1,101	)
	Decreases due to lapse of applicable statute of limitation		—			(868	)		(24,700	)
	Balance at end of period	$	9,524		$	5,730		$	4,487
Components of Deferred Tax Assets and Liabilities	Significant components of deferred tax assets and liabilities as of December 31, 2014 and 2013 were as follows:
		December 31,
		2014			2013
		(In thousands)
	Deferred tax assets:
	Pension liability	$	210,580		$	105,370
	Accrued warranty expense		16,116			18,003
	Accrued vacation pay		12,968			12,865
	Accrued liabilities for self-insurance (including postretirement health care benefits)		27,881			33,349
	Accrued liabilities for executive and employee incentive compensation		26,731			45,413
	Environmental and products liabilities		22,353			8,858
	Investments in joint ventures and affiliated companies		23,285			23,780
	Long-term contracts		13,885			37,684
	Net operating loss carryforward		13,931			12,539
	State tax net operating loss carryforward		19,417			21,252
	Foreign tax credit carryforward		2,959			320
	Other		24,362			7,135
	Total deferred tax assets		414,468			326,568
	Valuation allowance for deferred tax assets		(22,196	)		(24,872	)
	Deferred tax assets		392,272			301,696
	Deferred tax liabilities:
	Property, plant and equipment		20,004			35,797
	Long-term contracts		27,707			27,628
	Intangibles		32,220			29,388
	Other		9,716			8,631
	Total deferred tax liabilities		89,647			101,444
	Net deferred tax assets	$	302,625		$	200,252
Income Before Provision for Income Taxes	Income before provision for income taxes was as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	U.S.	$	(4,705	)	$	399,263		$	222,840
	Other than U.S.		10,171			117,910			96,578
	Income before provision for income taxes	$	5,466		$	517,173		$	319,418
Components of Provision for Income Taxes	The provision for income taxes consisted of:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Current:
	U.S. – federal	$	67,010		$	70,660		$	39,784
	U.S. – state and local		5,955			6,388			7,979
	Other than U.S.		6,741			13,467			11,060
	Total current		79,706			90,515			58,823
	Deferred:
	U.S. – Federal		(86,022	)		69,810			24,560
	U.S. – State and local		(3,945	)		6,546			6,545
	Other than U.S.		(5,730	)		17,712			11,933
	Total deferred (benefit) provision		(95,697	)		94,068			43,038
	Provision for income taxes	$	(15,991	)	$	184,583		$	101,861
Reconciliation of U.S. Statutory Federal Tax Rate to Consolidated and Combined Effective Tax Rate	The following is a reconciliation of the U.S. statutory federal tax rate (35%) to the consolidated effective tax rate:
		Year Ended December 31,
		2014			2013			2012
	U.S. federal statutory (benefit) rate		35	%		35	%		35	%
	State and local income taxes		(10.1	)		2.5			4.3
	Foreign rate differential		(72.5	)		(2.5	)		(4.1	)
	Foreign operations		19.5			—			0.5
	Tax credits		(75.0	)		(2.0	)		(2.5	)
	Dividends and deemed dividends from affiliates		(70.0	)		1.2			2.3
	Valuation allowances		(49.0	)		0.9			3.4
	Uncertain tax positions		25.2			0.3			(9.0	)
	Non-deductible expenses		52.7			0.4			1.3
	Manufacturing deduction		(169.9	)		(1.4	)		(1.3	)
	Minority interest		28			1			1.1
	Other		(6.5	)		0.3			0.9
	Effective tax rate		(292.6	)%		35.7	%		31.9	%
Valuation Allowance for Deferred Tax Assets	The following is an analysis of our valuation allowance for deferred tax assets:
		Beginning			Charges To			Charged To			Ending
		Balance			Costs and			Other			Balance
					Expenses			Accounts
		(In thousands)
	Year Ended December 31, 2014	$	(24,872	)		2,676			—		$	(22,196	)
	Year Ended December 31, 2013	$	(19,979	)		(4,893	)		—		$	(24,872	)
	Year Ended December 31, 2012	$	(9,354	)		(10,625	)		—		$	(19,979	)

LongTerm_Debt_and_Notes_Payabl1

Long-Term Debt and Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Components of Long-Term Debt and Notes Payable
		December 31,
		2014			2013
		(In thousands)
	Long-term debt consists of:
	Secured Debt:
	Credit Facility	$	300,000		$	—
	Power Generation – various notes payable		—			444
	Other		—			3
			300,000			447
	Less: Amounts due within one year		15,000			222
	Long-term debt	$	285,000		$	225
	Notes payable and current maturities of long-term debt consist of:
	Short-term lines of credit	$	3,215		$	4,449
	Current maturities of long-term debt		15,000			222
	Total	$	18,215		$	4,671
	Weighted average interest rate on short term borrowings		2.6	%		6.6	%

Pension_Plans_and_Postretireme1

Pension Plans and Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2014
Obligations and Funded Status	Obligations and Funded Status
		Pension Benefits						Other Benefits Year
		Year Ended						Ended December 31,
		December 31,
		2014			2013			2014				2013
		(In thousands)
	Change in benefit obligation:
	Benefit obligation at beginning of period	$	2,570,095		$	2,779,990		$	95,906			$	116,256
	Service cost		37,878			46,417			777				975
	Interest cost		119,368			111,200			3,827				3,745
	Plan participants’ contributions		264			266			1,546				1,055
	Curtailments		772			—			—				—
	Amendments		305			3,105			—				—
	Acquisition		5,108			—			—				—
	Settlements		(23,339	)		(21,862	)		—				—
	Actuarial loss (gain)		366,146			(195,290	)		12,974				(16,335	)
	Foreign currency exchange rate changes		(20,709	)		(17,465	)		(691	)			(655	)
	Benefits paid		(146,900	)		(136,266	)		(7,902	)			(9,135	)
	Benefit obligation at end of period	$	2,908,988		$	2,570,095		$	106,437			$	95,906
	Change in plan assets:
	Fair value of plan assets at beginning of period	$	2,181,323		$	2,127,694		$	43,274			$	37,324
	Actual return on plan assets		288,630			155,071			(415	)			6,056
	Plan participants’ contributions		264			266			1,546				1,055
	Company contributions		63,649			70,681			5,248				7,974
	Settlements		(23,339	)		(21,862	)		—				—
	Foreign currency exchange rate changes		(19,183	)		(14,261	)		—				—
	Benefits paid		(146,900	)		(136,266	)		(7,902	)			(9,135	)
	Fair value of plan assets at the end of period		2,344,444			2,181,323			41,751				43,274
	Funded status	$	(564,544	)	$	(388,772	)	$	(64,686	)		$	(52,632	)
	Amounts recognized in the balance sheet consist of:
	Accrued employee benefits	$	(4,051	)	$	(54,391	)	$	(6,473	)		$	(9,438	)
	Accumulated postretirement benefit obligation		—			—			(58,213	)			(43,194	)
	Pension liability		(562,176	)		(334,538	)		—				—
	Prepaid pension		1,683			157			—				—
	Accrued benefit liability, net	$	(564,544	)	$	(388,772	)	$	(64,686	)		$	(52,632	)
	Amount recognized in accumulated comprehensive income (before taxes):
	Prior service cost (credit)	$	14,204		$	18,237		$	(2,181	)		$	(2,338	)
	Supplemental information:
	Plans with accumulated benefit obligation in excess of plan assets
	Projected benefit obligation	$	2,789,053		$	2,433,369			N/A				N/A
	Accumulated benefit obligation	$	2,770,436		$	2,406,269		$	106,437			$	95,906
	Fair value of plan assets	$	2,222,825		$	2,047,507		$	41,751			$	43,274
	Plans with plan assets in excess of accumulated benefit obligation
	Projected benefit obligation	$	119,935		$	136,726			N/A				N/A
	Accumulated benefit obligation	$	117,503		$	132,221		$	—			$	—
	Fair value of plan assets	$	121,619		$	133,816		$	—			$	—
Components of Net Periodic Benefit Cost
		Pension Benefits										Other Benefits Year Ended
		Year Ended										December 31,
		December 31,
		2014			2013			2012				2014				2013				2012
		(In thousands)
	Components of net periodic benefit cost:
	Service cost	$	37,878		$	46,417		$	46,828			$	777			$	975			$	1,138
	Interest cost		119,368			111,200			122,605				3,827				3,745				5,124
	Expected return on plan assets		(149,231	)		(147,621	)		(136,913	)			(2,295	)			(2,116	)			(1,930	)
	Amortization of prior service cost		2,672			3,158			3,579				(163	)			(148	)			(139	)
	Recognized net actuarial loss (gain)		229,053			(202,442	)		34,496				12,574				(20,483	)			(2,456	)
	Net periodic benefit cost (income)	$	239,740		$	(189,288	)	$	70,595			$	14,720			$	(18,027	)		$	1,737
Recognized Net Actuarial Loss (Gain) and the Affected Consolidated Statements of Income	The recognized net actuarial loss (gain) and the affected consolidated statements of income line items are as follows:
		Year Ended December 31,
		2014			2013			2012
		(In thousands)
	Cost of operations	$	223,269		$	(191,352	)	$	23,893
	Selling, general and administrative expenses		17,887			(31,384	)		7,997
	Other-net		471			(189	)		150
	Total	$	241,627		$	(222,925	)	$	32,040
Summary of Additional Information	Additional Information
		Pension Benefits						Other Benefits
		Year Ended						Year Ended
		December 31,						December 31,
		2014			2013			2014				2013
		(In thousands)
	Increase (decrease) in accumulated other comprehensive income due to actuarial losses - before taxes	$	(1,351	)	$	(3,105	)	$	—			$	—
Weighted Average Assumptions	Assumptions
		Pension Benefits						Other Benefits
		2014			2013			2014				2013
	Weighted average assumptions used to determine net periodic benefit obligations at December 31:
	Discount rate		3.99	%		4.78	%		3.74	%			4.23	%
	Rate of compensation increase		2.57	%		2.56	%		—				—
	Weighted average assumptions used to determine net periodic benefit cost for the years ended December 31:
	Discount rate		4.78	%		4.09	%		4.23	%			3.43	%
	Expected return on plan assets		7	%		7.06	%		5.73	%			5.74	%
	Rate of compensation increase		2.56	%		2.57	%		—				—
Assumed Health-Care Cost Trend Rates
		2014			2013
	Assumed health care cost trend rates at December 31
	Health care cost trend rate assumed for next year		7.5	%		8	%
	Rates to which the cost trend rate is assumed to decline (ultimate trend rate)		4.5	%		4.5	%
	Year that the rate reaches ultimate trend rate		2021			2021
Effect of One-Percentage-Point Change in Assumed Health-Care Cost Trend Rates	A one-percentage-point change in our assumed health-care cost trend rates would have the following effects:
		One-Percentage-			One-Percentage-
		Point Increase			Point Decrease
		(In thousands)
	Effect on total of service and interest cost	$	425		$	(331	)
	Effect on postretirement benefit obligation	$	8,802		$	(7,400	)
Summary of Total Investments Measured at Fair Value	The following is a summary of total investments for our plans measured at fair value at December 31, 2014:
		12/31/14			Level 1			Level 2				Level 3
		(In thousands)
	Pension and Other Benefits:
	Fixed Income	$	907,046		$	—		$	907,046			$	—
	Equities		141,471			141,471			—				—
	Commingled and Mutual Funds		839,472			24,852			814,620				—
	U.S. Government Securities		324,169			308,867			15,302				—
	Partnerships with Security Holdings		110,565			—			—				110,565
	Real Estate		4,831			—			—				4,831
	Cash and Accrued Items		58,641			51,700			6,941				—
	Total Assets	$	2,386,195		$	526,890		$	1,743,909			$	115,396
	The following is a summary of total investments for our plans measured at fair value at December 31, 2013:
		12/31/13			Level 1			Level 2				Level 3
		(In thousands)
	Pension and Other Benefits:
	Fixed Income	$	682,028		$	—		$	682,028			$	—
	Equities		144,438			144,438			—				—
	Commingled and Mutual Funds		861,354			31,083			830,271				—
	U.S. Government Securities		355,245			355,245			—				—
	Partnerships with Security Holdings		116,154			—			—				116,154
	Real Estate		6,214			—			—				6,214
	Cash and Accrued Items		59,164			48,087			11,077				—
	Total Assets	$	2,224,597		$	578,853		$	1,523,376			$	122,368
Summary of Changes in Plans' Level 3 Instruments Measured on Recurring Basis	The following is a summary of the changes in the Plans’ Level 3 instruments measured on a recurring basis for the years ended December 31, 2014 and 2013:
		Year ended December 31,
		2014			2013
		(In thousands)
	Balance at beginning of period	$	122,368		$	127,400
	Issuances and acquisitions		10,387			6,016
	Dispositions		(34,471	)		(31,471	)
	Realized gain		24,835			18,058
	Unrealized gain		(7,723	)		2,365
	Balance at end of period	$	115,396		$	122,368
Cash Flows	Cash Flows
		Domestic Plans						Foreign Plans
		Pension			Other			Pension				Other
		Benefits			Benefits			Benefits				Benefits
		(In thousands)
	Expected employer contributions to trusts of defined benefit plans:
	2015	$	330		$	2,271		$	14,618				N/A
	Expected benefit payments:
	2015	$	140,258		$	8,245		$	10,538			$	513
	2016		145,703			7,832			10,832				501
	2017		150,335			7,428			11,144				519
	2018		154,417			7,258			11,536				544
	2019		157,714			7,233			11,909				545
	2020-2024		813,034			32,172			64,854				2,873
Summary of Contributions to Multiemployer Plans	The following table summarizes our contributions to multiemployer plans for the years covered by this report:
	Pension Fund	EIN/PIN			Pension Protection			FIP/RP  Status		Contributions														Expiration Date
					Act Zone			Pending/																Of Collective
					Zone Status			Implemented		2014				2013				2012				Surcharge		Bargaining
					2014		2013			(in millions)												Imposed		Agreement
	Boilermaker-Blacksmith National Pension Trust		48-6168020/		Yellow		Yellow	Yes		$	16			$	19			$	18.9				No	Described
			1																					Below
	All Other										4.6				11.9				5.3
										$	20.6			$	30.9			$	24.2
Foreign Plans [Member]
Plan Asset Allocations by Asset Category	The combined weighted average asset allocations of these plans at December 31, 2014 and 2013 by asset category were as follows:
		2014			2013
	Asset Category:
	Equity Securities and Commingled Mutual Funds		55	%		58	%
	Fixed Income		43	%		39	%
	Other		2	%		3	%
	Total		100	%		100	%
Target Allocation by Asset Class	The target allocation for 2015 for the foreign plans, by asset class, is as follows:
		Canadian			Diamond
		Plans			UK Plan
	Asset Class:
	U. S. Equity		17	%		12	%
	Global Equity		38	%		15	%
	Fixed Income		45	%		73	%
Domestic Plans [Member]
Plan Asset Allocations by Asset Category	The following is a summary of the asset allocations for the Master Trust at December 31, 2014 and 2013 by asset category:
		2014			2013
	Asset Category:
	Fixed Income (excluding U. S. Government Securities)		38	%		30	%
	Commingled and Mutual Funds		33	%		36	%
	U.S. Government Securities		15	%		18	%
	Equity Securities		7	%		7	%
	Partnerships with Security Holdings		5	%		6	%
	Real Estate		1	%		1	%
	Other		1	%		2	%
	Total		100	%		100	%
Target Allocation by Asset Class	The target allocation for 2015 for the domestic plans, by asset class, is as follows:
	Asset Class:
	Fixed Income		55	%
	Equities		45	%

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
B&W Stock Options [Member]
Schedule of Assumptions Used to Calculate Fair Value of Option Grant	The fair value of each option grant was estimated at the date of grant using Black-Scholes, with the following weighted-average assumptions:
		Year Ended
		December 31,
		2014			2013			2012
	Risk-free interest rate		0.97	%		0.56	%		0.65	%
	Expected volatility		0.3			0.33			0.36
	Expected life of the option in years		3.76			3.93			3.98
	Expected dividend yield		1.22	%		1.19	%		0	%
Summarized Activity of Stock Options	The following table summarizes activity for our stock options for the year ended December 31, 2014 (share data in thousands):
		Number			Weighted-			Weighted-			Aggregate
		of			Average			Average			Intrinsic
		Shares			Exercise			Remaining			Value
					Price			Contractual			(in  millions)
								Term
	Outstanding at beginning of period		1,974		$	26,87
	Granted		943			32.66
	Exercised		(194	)		21.5
	Cancelled/expired/forfeited		(176	)		30.88
	Outstanding at end of period		2,547		$	29.15			4.9 Years		$	6.3
	Exercisable at end of period		989		$	27.76			3.7 Years		$	3.8
B&W Performance Shares [Member]
Schedule of Restricted Stock Units	Nonvested performance shares as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (share data in thousands):
		Number			Weighted-
		of			Average
		Shares			Grant Date
					Fair Value
	Nonvested at beginning of period		834		$	29.07
	Adjustment to assumed vesting percentage		(294	)		27.38
	Granted		365			32.79
	Vested		(270	)		32.77
	Cancelled/forfeited		(100	)		29.38
	Nonvested at end of period		535		$	30.64
B&W Restricted Stock Units [Member]
Schedule of Restricted Stock Units	Nonvested restricted stock units as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (share data in thousands):
		Number			Weighted-
		of			Average
		Shares			Grant Date
					Fair Value
	Nonvested at beginning of period		385		$	26.78
	Granted		225			32.84
	Vested		(206	)		28.43
	Cancelled/forfeited		(28	)		29.02
	Nonvested at end of period		376		$	29.33
Cash-Settled Stock Appreciation Rights (SARs) [Member]
Schedule of Assumptions Used to Calculate Fair Value of Option Grant	The fair value of each stock appreciation right grant was calculated at the grant date using Black-Scholes and was remeasured at the end of the reporting period with the following weighted-average assumptions:
		Year Ended
		December 31,
		2014			2013			2012
	Risk-free interest rate		1.12	%		0.77	%		0.5	%
	Expected volatility		0.25			0.3			0.32
	Expected life of the option in years		3.21			3.21			3.55
	Expected dividend yield		1.42	%		1.19	%		1.23	%
Schedule of Summarized Activity of Stock Appreciation	The following table summarizes activity for our stock appreciation rights for the year ended December 31, 2014 (unit data in thousands):
		Number			Weighted-			Weighted-			Aggregate
		of			Average			Average			Intrinsic
		Units			Exercise			Remaining			Value
					Price			Contractual			(in  millions)
								Term
	Outstanding at beginning of period		96		$	26.35
	Granted		66			32.69
	Exercised		(15	)		26.07
	Cancelled/expired/forfeited		(44	)		30.28
	Outstanding at end of period		103		$	28.72			5.4 Years		$	0.3
	Exercisable at end of period		40		$	26.35			5.0 Years		$	0.2
Cash Settled Performance Units [Member]
Schedule of Restricted Stock Units	Nonvested cash-settled performance units as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (unit data in thousands):
		Number			Weighted-
		of			Average
		Units			Fair  Value
	Nonvested at beginning of period		51
	Adjustment to assumed vesting percentage		(21	)
	Granted		34
	Vested		—
	Cancelled/forfeited		(27	)
	Nonvested at end of period		37		$	30.3
Cash Settled Restricted Stock Units [Member]
Schedule of Restricted Stock Units	Nonvested restricted stock units as of December 31, 2014 and changes during the year ended December 31, 2014 were as follows (unit data in thousands):
		Number			Weighted-
		of			Average
		Units			Fair  Value
	Nonvested at beginning of period		23
	Granted		12
	Vested		(13	)
	Cancelled/forfeited		(9	)
	Nonvested at end of period		13		$	30.3

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Payments for Operating Leases	Future minimum payments required under operating leases that have initial or remaining noncancellable lease terms in excess of one year at December 31, 2014 are as follows (in thousands):
	Fiscal Year Ending December 31,	Amount
	2015	$	9,896
	2016	$	7,049
	2017	$	6,067
	2018	$	4,956
	2019	$	3,489
	Thereafter	$	1,221

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Investments Schedule [Abstract]
Summary of Available for Sale Securities
	The following is a summary of our investments at December 31, 2014:
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair  Value
				Gains		Losses
		(In thousands)
	Trading securities
	Corporate bonds – Centrus Energy Corp.	$	2,628	$	—	$	(189	)	$	2,439
	Available-for-sale securities
	Equities – Centrus Energy Corp.	$	3,088	$	—	$	—		$	3,088
	Mutual funds		3,906		293		—			4,199
	Asset-backed securities and collateralized mortgage obligations		370		—		(51	)		319
	Commercial paper		2,398		—		—			2,398
	Total	$	12,390	$	293	$	(240	)	$	12,443
	The following is a summary of our available-for-sale securities at December 31, 2013:
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair  Value
				Gains		Losses
		(In thousands)
	U.S. Government and agency securities	$	2,999	$	1	$	—		$	3,000
	Mutual funds		3,752		249		—			4,001
	Asset-backed securities and collateralized mortgage obligations		472		8		(55	)		425
	Commercial paper		7,748		—		—			7,748
	Total	$	14,971	$	258	$	(55	)	$	15,174
Summary of Proceeds, Gross Realized Gains and Gross Realized Losses on Sales of Available for Sale Securities	Proceeds, gross realized gains and gross realized losses on sales of available-for-sale securities is as follows:
		Proceeds		Gross		Gross
				Realized  Gains		Realized
						Losses
		(In thousands)
	Year Ended December 31, 2014	$	32,089	$	172	$	—
	Year Ended December 31, 2013	$	168,879	$	1,127	$	—
	Year Ended December 31, 2012	$	247,649	$	35	$	—

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Derivative Financial Instruments	The following tables summarize our derivative financial instruments at December 31, 2014 and 2013:
		Asset and Liability Derivatives
		December 31,
		2014			2013
		(In thousands)
	Derivatives Designated as Hedges:
	Foreign Exchange Contracts:
	Location
	Accounts receivable-other	$	541		$	1,139
	Other assets	$	—		$	94
	Accounts payable	$	2,744		$	581
	Other liabilities	$	743		$	603
	Derivatives Not Designated as Hedges:
	Foreign Exchange Contracts:
	Location
	Accounts receivable-other	$	176		$	464
	Other assets	$	—		$	50
	Accounts payable	$	284		$	10
Schedule of Effect of Derivative Instruments on Statements of Financial Performance	The effects of derivatives on our financial statements are outlined below:
		December 31,
		2014			2013
		(In thousands)
	Derivatives Designated as Hedges:
	Cash Flow Hedges:
	Foreign Exchange Contracts:
	Amount of loss recognized in other comprehensive income	$	(3,184	)	$	(5,936	)
	Gain (loss) reclassified from accumulated other comprehensive income into earnings: effective portion
	Location
	Revenues	$	620		$	(1,885	)
	Cost of operations	$	(2,793	)	$	(2,174	)
	Other-net	$	4		$	144
	Loss recognized in income: portion excluded from effectiveness testing
	Location
	Other-net	$	(104	)	$	(349	)
	Derivatives Not Designated as Hedges:
	Forward Contracts:
	Gain (loss) recognized in income
	Location
	Other-net	$	(184	)	$	96

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Summary of Investments and Available-for-Sale Securities Measured at Fair Value	The following is a summary of our investments measured at fair value at December 31, 2014:
		12/31/14		Level 1		Level 2		Level 3
		(In thousands)
	Trading securities
	Corporate bonds – Centrus Energy Corp.	$	2,439	$	2,439	$	—	$	—
	Available-for-sale securities
	Equities – Centrus Energy Corp.	$	3,088	$	—	$	3,088	$	—
	Mutual funds		4,199		—		4,199		—
	Asset-backed securities and collateralized mortgage obligations		319				319		—
	Commercial paper		2,398				2,398		—
	Total	$	12,443	$	2,439	$	10,004	$	—
	The following is a summary of our available-for-sale securities measured at fair value at December 31, 2013:
		12/31/13		Level 1		Level 2		Level 3
		(In thousands)
	Mutual funds	$	4,001	$	—	$	4,001	$	—
	U.S. Government and agency securities		3,000		3,000		—		—
	Asset-backed securities and collateralized mortgage obligations		425		—		425		—
	Commercial paper		7,748		—		7,748		—
	Total	$	15,174	$	3,000	$	12,174	$	—

Segment_Reporting_Tables

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Schedule of Operating Results by Segment	1. Information about Operations in our Different Industry Segments:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	REVENUES (1):
	Power Generation		$	1,486,029		$	1,767,651		$	1,785,959
	Nuclear Operations			1,220,952			1,167,683			1,098,031
	Technical Services			84,834			104,254			107,851
	Nuclear Energy			154,721			283,857			325,655
	mPower			278			1,523			326
	Adjustments and Eliminations			(23,795	)		(55,760	)		(26,463	)
			$	2,923,019		$	3,269,208		$	3,291,359
	(1)	Segment revenues are net of the following intersegment transfers and other adjustments:
	Power Generation Transfers		$	5,896		$	37,552		$	7,932
	Nuclear Operations Transfers			9,922			6,773			6,015
	Technical Services Transfers			57			3,817			3,496
	Nuclear Energy Transfers			7,920			7,618			8,992
	mPower Transfers			—			—			28
			$	23,795		$	55,760		$	26,463
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	OPERATING INCOME:
	Power Generation		$	98,557		$	155,837		$	183,387
	Nuclear Operations			270,536			237,855			226,269
	Technical Services			35,203			58,234			59,655
	Nuclear Energy			(23,211	)		8,641			50,649
	mPower			(68,946	)		(81,304	)		(113,528	)
			$	312,139		$	379,263		$	406,432
	Unallocated Corporate(1)			(32,514	)		(26,039	)		(27,953	)
	Special Charges for Restructuring Activities			(41,091	)		(39,599	)		—
	Mark to Market Adjustment			(241,156	)		222,737			(31,890	)
	Total Operating Income(2)		$	(2,622	)	$	536,362		$	346,589
	Other Income (Expense):
	Interest income			1,028			1,443			1,491
	Interest expense			(7,579	)		(3,115	)		(3,735	)
	Other - net			14,639			(17,517	)		(24,927	)
	Total Other Expense			8,088			(19,189	)		(27,171	)
	Income before Provision for Income Taxes		$	5,466		$	517,173		$	319,418
	(1)        Unallocated corporate includes general corporate overhead not allocated to segments
	(2)        Included in operating income is the following:
	(Gains) Losses on Asset Disposals – Net:
	Power Generation		$	1,752		$	1,181		$	3,276
	Nuclear Operations			—			163			(339	)
	Technical Services			—			—			(1,517	)
	Nuclear Energy			(665	)		(28	)		(1	)
	mPower			—			—			—
	Unallocated Corporate			(6	)		(267	)		—
			$	1,081		$	1,049		$	1,419
	Equity in Income of Investees:
	Power Generation		$	8,682		$	18,388		$	17,402
	Nuclear Operations			—			—			—
	Technical Services			33,042			50,281			49,621
	Nuclear Energy			32			(611	)		(314	)
	mPower			—			—			—
			$	41,756		$	68,058		$	66,709
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	SEGMENT ASSETS:
	Power Generation		$	1,018,149		$	970,718		$	1,059,824
	Nuclear Operations			770,359			778,203			708,607
	Technical Services			114,581			120,559			125,494
	Nuclear Energy			427,412			439,325			391,096
mPower			17,233			21,790			10,137
Total Segment Assets			2,347,734			2,330,595			2,295,158
Corporate Assets			509,202			278,558			545,197
Total Assets		$	2,856,936		$	2,609,153		$	2,840,355
CAPITAL EXPENDITURES:
Power Generation		$	15,449		$	15,280		$	24,592
Nuclear Operations			34,777			31,572			44,810
Technical Services			66			98			—
Nuclear Energy			14,358			5,506			5,881
mPower			1,983			2,854			2,554
Segment Capital Expenditures			66,633			55,310			77,837
Corporate Capital Expenditures			9,396			9,640			8,798
Total Capital Expenditures		$	76,029		$	64,950		$	86,635
DEPRECIATION AND AMORTIZATION:
Power Generation		$	30,661		$	23,892		$	19,126
Nuclear Operations			54,524			26,975			32,013
Technical Services			3			185			244
Nuclear Energy			6,564			6,520			5,923
mPower			974			554			279
Segment Depreciation and Amortization			92,726			58,126			57,585
Corporate Depreciation and Amortization			13,072			12,399			12,112
Total Depreciation and Amortization		$	105,798		$	70,525		$	69,697
INVESTMENT IN UNCONSOLIDATED AFFILIATES:
Power Generation		$	109,248		$	144,475		$	139,399
Nuclear Operations			—			—			—
Technical Services			31,229			40,329			46,928
Nuclear Energy			27			27			27
mPower			—			—			—
Total Investment in Unconsolidated Affiliates		$	140,504			184,831		$	186,354
Schedule of Revenue Information from Products and Service Lines	2. Information about our Product and Service Lines:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	REVENUES:
	Power Generation:
	New Build Environmental Equipment		$	234,475		$	434,228		$	446,514
	New Build Steam Generation Systems			358,539			454,277			511,201
	Aftermarket Services			796,061			885,185			841,571
	Industrial Environmental			105,400			—			—
	Eliminations/Other			(8,446	)		(6,039	)		(13,327	)
				1,486,029			1,767,651			1,785,959
	Nuclear Operations:
	Nuclear Component Program			1,208,505			1,153,216			1,086,081
	Commercial Operations			773			7,681			5,908
	Eliminations/Other			11,674			6,786			6,042
				1,220,952			1,167,683			1,098,031
	Technical Services:
	Commercial Operations			10,897			21,227			20,819
	Nuclear Environmental Services			70,998			73,043			78,228
	Management & Operation Contracts of U.S. Government Facilities			2,939			9,984			8,804
	Eliminations/Other			—			—			—
				84,834			104,254			107,851
	Nuclear Energy:
	Nuclear Services			105,078			113,180			158,365
	Nuclear Equipment			41,354			83,449			134,011
	Nuclear Projects			8,289			87,002			33,319
	Eliminations/Other			—			226			(40	)
				154,721			283,857			325,655
	mPower:			278			1,523			326
	Eliminations			(23,795	)		(55,760	)		(26,463	)
			$	2,923,019		$	3,269,208		$	3,291,359
Schedule of Revenues by Geographical Area	3. Information about our Consolidated Operations in Different Geographic Areas:
			Year Ended December 31,
			2014			2013			2012
			(In thousands)
	REVENUES(1):
	United States		$	2,308,987		$	2,589,521		$	2,615,387
	Canada			193,786			313,881			288,246
	Denmark			65,436			56,336			18,504
	United Kingdom			61,972			20,927			6,653
	China			59,841			58,775			45,830
	Sweden			29,786			37,823			101,688
	Dominican Republic			27,399			473			687
	Germany			22,792			22,869			34,364
	Chile			15,686			9,240			11,582
	Korea			14,149			9,033			14,461
	Thailand			8,113			2,650			3,041
	Colombia			8,037			44,622			1,163
	Saudi Arabia			8,003			8,200			7,973
	Singapore			7,527			2,507			171
	France			7,057			3,930			2,384
	Indonesia			5,324			6,227			7,828
	India			5,070			4,670			13,306
	Finland			4,926			—			—
	Vietnam			3,829			1,946			459
	Italy			3,540			4,156			8,477
	Poland			3,343			1,748			415
	Norway			3,199			2,594			9,939
	Brazil			3,156			2,751			2,585
	South Africa			3,137			2,208			2,993
	Argentina			3,100			5,737			23,529
	Trinidad			2,546			3,264			2,401
	Australia			2,540			1,854			1,251
	Mexico			2,344			3,461			3,384
	Israel			2,088			2,919			2,502
	Venezuela			2,041			448			832
	Other Countries			34,265			44,438			59,324
			$	2,923,019		$	3,269,208		$	3,291,359
	(1)	We allocate geographic revenues based on the location of the customer’s operations.
Schedule of Property, Plant and Equipment, Net by Geographical Area	NET PROPERTY, PLANT AND EQUIPMENT:
	United States		$	366,288		$	367,672		$	363,447
	Canada			27,480			38,738			45,402
	China			12,356			10,980			7,926
	Mexico			12,106			8,312			8,302
	United Kingdom			8,638			9,414			9,714
	Denmark			6,963			8,715			8,565
	Germany			1,536			2,060			2,284
	Other Countries			1,268			1,188			1,381
			$	436,635		$	447,079		$	447,021

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Information	The following tables set forth selected unaudited quarterly financial information for the years ended December 31, 2014 and 2013:
			Year Ended December 31, 2014
			Quarter Ended
			March 31,		June 30,		Sept. 30,		Dec. 31,
			2014		2014		2014		2014
			(In thousands, except per share amounts)
	Revenues		$	662,017	$	686,006	$	737,902	$	837,094
	Operating income (1)		$	53,640	$	35,118	$	65,160	$	(156,540	)
	Equity in income of investees		$	15,269	$	13,183	$	7,308	$	5,996
	Net income attributable to The Babcock & Wilcox Company		$	45,044	$	26,437	$	61,214	$	(103,307	)
	Earnings per common share:
	Basic:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.24	$	0.57	$	(0.97	)
	Diluted:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.24	$	0.57	$	(0.97	)
	(1)	Includes equity in income of investees.
			Year Ended December 31, 2013
			Quarter Ended
			March 31,		June 30,		Sept. 30,		Dec. 31,
			2013		2013		2013		2013
			(In thousands, except per share amounts)
	Revenues		$	805,423	$	886,136	$	774,834	$	802,815
	Operating income (1)		$	60,213	$	98,706	$	82,121	$	295,322
	Equity in income of investees		$	14,787	$	18,775	$	18,151	$	16,345
	Net income attributable to The Babcock & Wilcox Company		$	47,174	$	72,870	$	60,446	$	165,588
	Earnings per common share:
	Basic:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.65	$	0.54	$	1.5
	Diluted:
	Net income attributable to The Babcock & Wilcox Company		$	0.41	$	0.65	$	0.54	$	1.48
	(1)	Includes equity in income of investees.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share:
			Year Ended December 31,
			2014		2013		2012
			(In thousands, except shares and
			per share amounts)
	Basic:
	Net income attributable to The Babcock & Wilcox Company		$	29,388	$	346,078	$	227,695
	Weighted average common shares			108,477,262		111,901,750		118,418,930
	Basic earnings per common share:
	Net income attributable to The Babcock & Wilcox Company		$	0.27	$	3.09	$	1.92
	Diluted:
	Net income attributable to The Babcock & Wilcox Company		$	29,388	$	346,078	$	227,695
	Weighted average common shares (basic)			108,477,262		111,901,750		118,418,930
	Effect of dilutive securities:
	Stock options, restricted stock and performance shares(1)			283,830		783,667		602,394
	Adjusted weighted average common shares			108,761,092		112,685,417		119,021,324
	Diluted earnings per common share:
	Net income attributable to The Babcock & Wilcox Company		$	0.27	$	3.07	$	1.91
	-1	At December 31, 2014, 2013 and 2012, we excluded from the diluted share calculation 1,698,106, 442,226, and 1,082,904 shares, respectively, related to stock options, as their effect would have been antidilutive.

Basis_of_Presentation_and_Sign3

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Supplier
	Location
	Reactors
	Facility
	Segment
	MW
	Country
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of business segments	5
Number of countries in which Company operates	30
Supplied electric generating capacity	300,000
Number of N-Stamp certified locations	2
Number of large, heavy-walled nuclear components and vessels suppliers	2
Number of reactors to be used	2
Net foreign currency transaction gains (losses) included in other expense	$1,900,000	$500,000	($600,000)
Revenue recognition, percentage of contract completion	70.00%
Increase in value of existing contract	70,500,000
Revenue recognized for the cumulative effect of contract change	46,400,000
Cost of operation	25,800,000
Contract losses	11,600,000	35,600,000	16,900,000
Long-term retainages, anticipated collection in 2016	1,800,000
Long-term retainages, anticipated collection in 2017	5,900,000
Long-term retainages, anticipated collection in 2018	1,400,000
Number of facilities with U.S. Government decommissioning costs obligation	2
Research and development activities	142,800,000	200,800,000	173,900,000
Research and development activities, paid by customers	41,800,000	43,200,000	53,400,000
DOE funding	27,800,000	78,400,000
Research and development activities	5,831,000	15,794,000	17,942,000
Pre-award costs under the program		21,500,000	9,700,000
Percentage of total inventories using LIFO method	17.00%	18.00%
LIFO reserve	7,900,000	7,700,000
Depreciation expense	92,900,000	62,200,000	59,400,000
Impairment charges recognized	1,730,000	1,260,000	3,216,000
Interest expense	9,500,000	4,800,000	4,900,000
Interest Costs Capitalized	1,900,000	1,700,000	1,200,000
Restricted cash and cash equivalents	57,200,000
Restricted cash and cash equivalents	54,497,000	45,945,000
Reserves for self-insurance	32,800,000	37,800,000
Power Generation [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of countries in which Company operates	90
Number of facilities in which Company operates	800
Generation mPower LLC [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Research and development activities	5,800,000	15,800,000	17,900,000
Minimum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of large, heavy components supplied to worldwide	1,300
Minimum [Member] | Buildings [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated economic useful life	8 years
Minimum [Member] | Machinery and Equipment [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated economic useful life	3 years
Maximum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Investment ownership in percentage	20.00%
Maximum [Member] | Buildings [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated economic useful life		33 years
Maximum [Member] | Machinery and Equipment [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated economic useful life		28 years
Maximum [Member] | mPower [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Investment for development	15,000,000
Restricted Foreign Cash [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	3,700,000
Cash Held for Future Decommissioning of Facilities [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	2,700,000
Cash Held to Meet Reinsurance Reserve Requirements [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	$50,800,000

Basis_of_Presentation_and_Sign4

Basis of Presentation and Significant Accounting Policies - Contracts in Progress and Advance Billings (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Collaboration Arrangement Disclosure [Abstract]
Costs incurred less costs of revenue recognized	$183,312	$150,724
Revenues recognized less billings to customers	215,061	220,096
Contracts In Progress	398,373	370,820
Billings to customers less revenues recognized	274,151	411,156
Costs incurred less costs of revenue recognized	-18,616	-93,385
Advance Billings on Contracts	$255,535	$317,771

Basis_of_Presentation_and_Sign5

Basis of Presentation and Significant Accounting Policies - Retainages on Contracts (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Collaboration Arrangement Disclosure [Abstract]
Retainages expected to be collected within one year	$103,867	$84,389
Retainages expected to be collected after one year	9,092	12,820
Total retainages	$112,959	$97,209

Basis_of_Presentation_and_Sign6

Basis of Presentation and Significant Accounting Policies - Accumulated Other Comprehensive Income (Detail) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Collaboration Arrangement Disclosure [Abstract]
Currency translation adjustments	$11,547	$38,415
Net unrealized gain on available-for-sale investments	155	130
Net unrealized gain (loss) on derivative financial instruments	-123	627
Unrecognized prior service cost on benefit obligations	-7,983	-10,824
Accumulated other comprehensive income	$3,596	$28,348

Basis_of_Presentation_and_Sign7

Basis of Presentation and Significant Accounting Policies - Schedule of Amounts Reclassified from Accumulated Other Comprehensive Income (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenues	$837,094,000	$737,902,000	$686,006,000	$662,017,000	$802,815,000	$774,834,000	$886,136,000	$805,423,000	$2,923,019,000	$3,269,208,000	$3,291,359,000
Other - net									14,639,000	-17,517,000	-24,927,000
Selling, general and administrative expenses									-442,615,000	-379,382,000	-428,293,000
Income before Provision for Income Taxes									5,466,000	517,173,000	319,418,000
Provision for Income Taxes									15,991,000	-184,583,000	-101,861,000
Net Income									21,457,000	332,590,000	217,557,000
Accumulated Other Comprehensive Income Component Recognized [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassification for the period									-5,180,000	-4,148,000	-223,000
Accumulated Other Comprehensive Income Component Recognized [Member] | Realized (Loss) Gain on Derivative Financial Instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenues									620,000	-1,885,000	-1,082,000
Cost of operations									-2,793,000	-2,174,000	3,833,000
Other - net									4,000	144,000	-24,000
Income before Provision for Income Taxes									-2,169,000	-3,915,000	2,727,000
Provision for Income Taxes									559,000	973,000	-704,000
Net Income									-1,610,000	-2,942,000	2,023,000
Accumulated Other Comprehensive Income Component Recognized [Member] | Recognition of Prior Service Cost on Benefit Obligations [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of operations									-3,433,000	-2,813,000	-3,271,000
Selling, general and administrative expenses									-1,795,000	-197,000	-169,000
Income before Provision for Income Taxes									-5,228,000	-3,010,000	-3,440,000
Provision for Income Taxes									1,547,000	1,035,000	1,159,000
Net Income									-3,681,000	-1,975,000	-2,281,000
Accumulated Other Comprehensive Income Component Recognized [Member] | Realized Gain on Available-for-sale Investments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other - net									172,000	799,000	35,000
Provision for Income Taxes									-61,000	-30,000
Net Income									$111,000	$769,000	$35,000

Basis_of_Presentation_and_Sign8

Basis of Presentation and Significant Accounting Policies - Summary of Changes in Carrying Amount of Accrued Warranty Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Standard Product Warranty Disclosure [Abstract]
Balance at beginning of period	$56,436	$83,682	$97,209
Additions	14,993	18,486	20,972
Acquisition of MEGTEC	4,693
Expirations and other changes	-6,393	-24,801	-24,766
Payments	-14,807	-20,250	-10,217
Translation and other	-1,298	-681	484
Balance at end of period	$53,624	$56,436	$83,682

Basis_of_Presentation_and_Sign9

Basis of Presentation and Significant Accounting Policies - Asset Retirement Obligations (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset retirement obligations Abstract
Balance at beginning of period	$44,771	$42,366	$35,885
Costs incurred	0	0	0
Additions/Adjustments	418	-109	3,422
Accretion	2,622	2,514	3,059
Balance at end of period	$47,811	$44,771	$42,366

Recovered_Sheet1

Basis of Presentation and Significant Accounting Policies - Inventories (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory, Net [Abstract]
Raw Materials and Supplies	$81,530	$85,455
Work in Progress	9,831	10,872
Finished Goods	17,276	16,731
Total Inventories	$108,637	$113,058

Recovered_Sheet2

Basis of Presentation and Significant Accounting Policies - Property, Plant and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$1,167,581	$1,126,683
Less accumulated depreciation	730,946	679,604
Net Property, Plant and Equipment	436,635	447,079	447,021
Land [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	15,506	11,718
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	253,338	249,614
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	827,029	782,633
Property Under Construction [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$71,708	$82,718

Recovered_Sheet3

Basis of Presentation and Significant Accounting Policies - Changes in Carrying Amount of Goodwill (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Line Items]
Beginning balance	$281,708	$280,780
Purchase price adjustment for acquisition of MEGTEC (Note 2)	108,800
Currency translation adjustments and other	-11,316	928
Ending balance	379,192	281,708
Power Generation [Member]
Goodwill [Line Items]
Beginning balance	104,630	103,702
Purchase price adjustment for acquisition of MEGTEC (Note 2)	108,800
Currency translation adjustments and other	-4,152	928
Ending balance	209,278	104,630
Nuclear Operations [Member]
Goodwill [Line Items]
Beginning balance	118,103		118,103
Currency translation adjustments and other	-7,164
Ending balance	110,939		118,103
Technical Services [Member]
Goodwill [Line Items]
Beginning balance			45,000
Ending balance	45,000	45,000	45,000
Nuclear Energy [Member]
Goodwill [Line Items]
Beginning balance			13,975
Ending balance	$13,975	$13,975	$13,975

Recovered_Sheet4

Basis of Presentation and Significant Accounting Policies - Changes in Carrying Amount of Goodwill (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Collaboration Arrangement Disclosure [Abstract]
Changes from foreign currency translation adjustments		($7.20)
Changes from foreign currency translation adjustments	($4.20)	$0.90

Recovered_Sheet5

Basis of Presentation and Significant Accounting Policies - Schedule of Intangible Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Amortized intangible assets	$100,354	$66,026	$72,863
Accumulated amortization	-34,616	-29,640	-30,312
Net amortized intangible assets	65,738	36,386	42,551
Unamortized intangible assets	45,135	45,135	45,135
Customer Relationships [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Amortized intangible assets	57,539	35,383	36,644
Accumulated amortization	-17,011	-13,490	-11,173
Acquired Backlog [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Amortized intangible assets	10,600		2,979
Accumulated amortization	-5,300		-1,457
Tradename [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Amortized intangible assets	11,457	11,945	11,945
Accumulated amortization	-2,959	-8,015	-6,422
Unpatented Technology [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Amortized intangible assets	8,472	6,422	6,422
Accumulated amortization	-3,442	-3,335	-2,682
Patented Technology [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Amortized intangible assets	2,521	2,521	6,961
Accumulated amortization	-1,122	-806	-4,235
All Other [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Amortized intangible assets	9,765	9,755	7,912
Accumulated amortization	-4,782	-3,994	-4,343
NRC Category 1 License [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Unamortized intangible assets	43,830	43,830	43,830
Trademarks and Trade Names [Member]
Schedule Of Amortized And Unamortized Intangible Assets [Line Items]
Unamortized intangible assets	$1,305	$1,305	$1,305

Recovered_Sheet6

Basis of Presentation and Significant Accounting Policies - Changes in Carrying Amount of Intangible Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Collaboration Arrangement Disclosure [Abstract]
Balance at beginning of period	$81,521	$87,686	$103,041
Business acquisitions and adjustments	44,972	2,200	-1,746
Amortization expense	-12,923	-8,324	-11,010
Impairment charge	-1,730	-1,260	-3,216
Currency translation adjustments and other	-967	1,219	617
Balance at end of period	$110,873	$81,521	$87,686

Recovered_Sheet7

Basis of Presentation and Significant Accounting Policies - Estimated Amortization Expense (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Collaboration Arrangement Disclosure [Abstract]
2015	$13,360
2016	8,006
2017	7,912
2018	7,262
2019	$6,908

Recovered_Sheet8

Basis of Presentation and Significant Accounting Policies - Changes in Carrying Amount of Other Non-Current Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Collaboration Arrangement Disclosure [Abstract]
Balance at beginning of period	$6,518	$8,468	$5,723
Additions	5,473		4,902
Interest expense - debt issuance costs	-2,070	-1,950	-2,157
Balance at end of period	$9,921	$6,518	$8,468

Business_Acquisitions_and_Disp2

Business Acquisitions and Dispositions - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended			0 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	21-May-14	Jun. 20, 2014
Significant Acquisitions and Disposals [Line Items]
Payments to acquire business									$127,703,000		$318,000
Revenues	837,094,000	737,902,000	686,006,000	662,017,000	802,815,000	774,834,000	886,136,000	805,423,000	2,923,019,000	3,269,208,000	3,291,359,000
Net Income	-103,307,000	61,214,000	26,437,000	45,044,000	165,588,000	60,446,000	72,870,000	47,174,000	29,388,000	346,078,000	227,695,000
Elimination of acquisition related costs									14,400,000
Nuclear Projects [Member]
Significant Acquisitions and Disposals [Line Items]
Income (loss) before provision for income taxes									-4,500,000	-2,700,000
Accounts receivable	45,400,000								45,400,000
Acquisition-related Costs [Member]
Significant Acquisitions and Disposals [Line Items]
Elimination of historical interest expense									900,000	2,400,000
Interest expense associated with incremental borrowings									1,200,000	2,500,000
Acquisition-related Costs [Member] | Finite-Lived Intangible Assets [Member]
Significant Acquisitions and Disposals [Line Items]
Increase (decrease) in amortization expense related to identifiable intangible assets									-3,900,000	12,600,000
Ebensberg Power Company [Member]
Significant Acquisitions and Disposals [Line Items]
Payment to acquire business												1,300,000
Business acquisition, cash acquired												16,400,000
Business acquisition, plant and equipment acquired												16,100,000
MEGTEC Holdings Inc [Member]
Significant Acquisitions and Disposals [Line Items]
Payments to acquire business													142,800,000
Revenues									105,400,000
Net Income									3,300,000
Business acquisition, cash acquired	14,232,000								14,232,000
Business acquisition, plant and equipment acquired	$5,090,000								$5,090,000

Business_Acquisitions_and_Disp3

Business Acquisitions and Dispositions - Summary of Purchase Price Allocation Including Finalization of Asset Valuations (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill	$379,192	$281,708	$280,780
MEGTEC Holdings Inc [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	14,232
Accounts receivable	23,054
Inventories	5,395
Other current assets	9,200
Property, plant and equipment	5,090
Goodwill	108,800
Intangible assets	44,250
Total assets acquired	210,021
Accounts payable	13,402
Advance billings on contracts	11,144
Other current liabilities	18,089
Pension liability	5,041
Deferred income taxes	5,202
Other liabilities	130
Total liabilities assumed	53,008
Net assets acquired	157,013
Net assets acquired	157,013
Cash and cash equivalents acquired	14,232
Net assets acquired, net of unrestricted cash acquired	142,781
Amount of tax deductible goodwill	$34,583

Business_Acquisitions_and_Disp4

Business Acquisitions and Dispositions - Summary of Intangible Assets Acquired (Detail) (MEGTEC Holdings Inc [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, Amount	$44,250
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, Amount	24,400
Intangible assets, Amortization Period	7 years
Backlog [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, Amount	10,600
Intangible assets, Amortization Period	1 year
Trademarks and Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, Amount	6,000
Intangible assets, Amortization Period	15 years
Developed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, Amount	$3,250
Intangible assets, Amortization Period	10 years

Business_Acquisitions_and_Disp5

Business Acquisitions and Dispositions - Summary of Unaudited Pro Forma Financial Information (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition, Pro Forma Information [Abstract]
Revenues	$3,003,351	$3,445,597
Net Income Attributable to The Babcock & Wilcox Company	$36,357	$341,774
Basic Earnings per Common Share	$0.34	$3.05
Diluted Earnings per Common Share	$0.33	$3.03

Equity_Method_Investments_Addi

Equity Method Investments - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity Method Investments and Joint Ventures [Abstract]
Undistributed earnings of equity method investees	$104.60	$113
Reimbursable costs included in revenues of equity method investees	1,386.60	2,121	2,222.40
Investment in equity method investees in excess of underlying equity in net assets	4.5
Gain on sale of interest in joint venture			$1.20

Equity_Method_Investments_Summ

Equity Method Investments - Summary of Combined Income Statement Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Equity Method Investments and Joint Ventures [Abstract]
Current assets	$706,845	$800,704
Noncurrent assets	181,517	252,430
Total Assets	888,362	1,053,134
Current liabilities	507,616	610,329
Noncurrent liabilities	97,419	72,742
Owners' equity	283,327	370,063
Total Liabilities and Owners' Equity	$888,362	$1,053,134

Equity_Method_Investments_Summ1

Equity Method Investments - Summary of Combined Balance Sheet Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity Method Investments and Joint Ventures [Abstract]
Revenues	$2,109,159	$2,832,202	$2,758,159
Gross profit	157,472	208,714	210,425
Income before provision for income taxes	95,013	150,511	146,911
Provision for income taxes	6,160	8,603	9,000
Net Income	$88,853	$141,908	$137,911

Equity_Method_Investments_Reco

Equity Method Investments - Reconciliation of Net Income to Equity in Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity Method Investments and Joint Ventures [Abstract]
Equity income based on stated ownership percentages	$43,263				$68,305				$43,263	$68,305	$66,064
All other adjustments due to amortization of basis differences, timing of GAAP adjustments and other adjustments	-1,507				-247				-1,507	-247	645
Equity in Income of Investees	$5,996	$7,308	$13,183	$15,269	$16,345	$18,151	$18,775	$14,787	$41,756	$68,058	$66,709

Equity_Method_Investments_Sche

Equity Method Investments - Schedule of Transactions with Unconsolidated Affiliates (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity Method Investments and Joint Ventures [Abstract]
Sales to	$87,722	$99,443	$42,538
Purchases from	5,623	4,645	1,814
Dividends received	60,519	79,595	51,594
Capital contributions, net of returns	$4,900	$6,884	$6,289

Special_Charges_for_Restructur2

Special Charges for Restructuring Activities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Consulting and administrative costs	$900,000
Special charges for restructuring activities	41,091,000	39,599,000
Employee termination benefits	8,800,000
Business Optimization Project [Member]
Restructuring Cost and Reserve [Line Items]
Employee Termination Benefits	12,800,000
Facility consolidation	10,800,000
Special charges for restructuring activities	26,800,000
Consulting and administrative costs	3,200,000
mPower Program Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Employee Termination Benefits	7,300,000
Facility consolidation	300,000
Special charges for restructuring activities	10,600,000
Consulting and administrative costs	3,000,000
Technical Services Segment Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Employee Termination Benefits	400,000
Global Competitiveness Initiative [Member]
Restructuring Cost and Reserve [Line Items]
Employee Termination Benefits	200,000	23,700,000
Facility consolidation	3,100,000	7,400,000
Consulting and administrative costs		$8,500,000

Special_Charges_for_Restructur3

Special Charges for Restructuring Activities - Changes in Restructuring Liabilities (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restructuring and Related Activities [Abstract]
Liability balance at the beginning of the period	$10,054
Special charges for restructuring activities	30,298	36,150
Payments	-30,321	-26,096
Translation and other	-366
Liability balance at the end of the period	$9,665	$10,054

Special_Charges_for_Restructur4

Special Charges for Restructuring Activities - Changes in Restructuring Liabilities (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restructuring and Related Activities [Abstract]
Non-cash charges	$10.80	$3.40

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Balance at beginning of period	$5,730	$4,487	$32,357
Increases based on tax positions taken in the current year	868	732	980
Increases based on tax positions taken in the prior years	3,536	1,546	65
Decreases based on tax positions taken in the prior years	-260	-167	-3,114
Decreases due to settlements with tax authorities	-350		-1,101
Decreases due to lapse of applicable statute of limitation		-868	-24,700
Balance at end of period	$9,524	$5,730	$4,487

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Contingency [Line Items]
Unrecognized tax benefits that would reduce effective tax rate if recognized	$9,524,000	$5,730,000	$4,487,000	$32,357,000
Amount of tax redused in the effective tax rate	7,300,000
Increase in accruals	500,000
Liability for the payment of tax related interest and penalties	900,000	400,000	300,000
Valuation Allowance for deferred tax asset	22,196,000	24,872,000	19,979,000	9,354,000
Undistributed earnings of subsidiaries	347,100,000
Unrecognized deferred income tax liabilities	44,100,000
Tax benefit on earnings with intent to remit	600,000
Foreign [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards	11,100,000
Foreign net operating loss carryforwards scheduled to expire	900,000
Foreign tax credit carryovers	2,900,000
Net operating loss carryforwards, expiration date	2015
Foreign [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration date	2017
Foreign [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration date	2033
State [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards	29,900,000
Net operating loss carryforwards, valuation allowance	18,700,000
State [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration date	2015
Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Decrease in unrecognized tax benefits	($3,000,000)

Income_Taxes_Components_of_Def

Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Deferred tax assets:
Pension liability	$210,580	$105,370
Accrued warranty expense	16,116	18,003
Accrued vacation pay	12,968	12,865
Accrued liabilities for self-insurance (including postretirement health care benefits)	27,881	33,349
Accrued liabilities for executive and employee incentive compensation	26,731	45,413
Environmental and products liabilities	22,353	8,858
Investments in joint ventures and affiliated companies	23,285	23,780
Long-term contracts	13,885	37,684
Net operating loss carryforward	13,931	12,539
State tax net operating loss carryforward	19,417	21,252
Foreign tax credit carryforward	2,959	320
Other	24,362	7,135
Total deferred tax assets	414,468	326,568
Valuation allowance for deferred tax assets	-22,196	-24,872	-19,979	-9,354
Deferred tax assets	392,272	301,696
Deferred tax liabilities:
Property, plant and equipment	20,004	35,797
Long-term contracts	27,707	27,628
Intangibles	32,220	29,388
Other	9,716	8,631
Total deferred tax liabilities	89,647	101,444
Net deferred tax assets	$302,625	$200,252

Income_Taxes_Income_Before_Pro

Income Taxes - Income Before Provision for Income Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S.	($4,705)	$399,263	$222,840
Other than U.S.	10,171	117,910	96,578
Income before Provision for Income Taxes	$5,466	$517,173	$319,418

Income_Taxes_Components_of_Pro

Income Taxes - Components of Provision for Income Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S. - federal	$67,010	$70,660	$39,784
U.S. - state and local	5,955	6,388	7,979
Other than U.S.	6,741	13,467	11,060
Total current	79,706	90,515	58,823
U.S. - Federal	-86,022	69,810	24,560
U.S. - State and local	-3,945	6,546	6,545
Other than U.S.	-5,730	17,712	11,933
Total deferred (benefit) provision	-95,697	94,068	43,038
Provision for income taxes	($15,991)	$184,583	$101,861

Income_Taxes_Reconciliation_of1

Income Taxes - Reconciliation of U.S. Statutory Federal Tax Rate to Consolidated and Combined Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S. federal statutory (benefit) rate	35.00%	35.00%	35.00%
State and local income taxes	-10.10%	2.50%	4.30%
Foreign rate differential	-72.50%	-2.50%	-4.10%
Foreign operations	19.50%		0.50%
Tax credits	-75.00%	-2.00%	-2.50%
Dividends and deemed dividends from affiliates	-70.00%	1.20%	2.30%
Valuation allowances	-49.00%	0.90%	3.40%
Uncertain tax positions	25.20%	0.30%	-9.00%
Non-deductible expenses	52.70%	0.40%	1.30%
Manufacturing deduction	-169.90%	-1.40%	-1.30%
Minority interest	28.00%	1.00%	1.10%
Other	-6.50%	0.30%	0.90%
Effective tax rate	-292.60%	35.70%	31.90%

Income_Taxes_Valuation_Allowan

Income Taxes - Valuation Allowance for Deferred Tax Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Beginning Balance	($24,872)	($19,979)	($9,354)
Charges To Costs and Expenses	2,676	-4,893	-10,625
Charged To Other Accounts	0	0	0
Ending Balance	($22,196)	($24,872)	($19,979)

LongTerm_Debt_and_Notes_Payabl2

Long-Term Debt and Notes Payable - Components of Long-Term Debt and Notes Payable (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]
Secured Debt: Credit Facility	$300,000
Power Generation - various notes payable		444
Other		3
Long-term debt, gross total	300,000	447
Long-term debt, gross total	300,000	447
Less: Amounts due within one year	15,000	222
Long-term Debt	285,000	225
Short-term lines of credit	3,215	4,449
Current maturities of long-term debt	15,000	222
Total	$18,215	$4,671
Weighted average interest rate on short term borrowings	2.60%	6.60%

LongTerm_Debt_and_Notes_Payabl3

Long-Term Debt and Notes Payable - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jun. 24, 2014
Debt Instrument [Line Items]
Short-term line of credit interest rate	6.30%
Amounts due within one year	$18,200,000
Maturity of long-term debt, 2016	15,000,000
Maturity of long-term debt, 2017	15,000,000
Maturity of long-term debt, 2018	15,000,000
Maturity of long-term debt, 2019	240,000,000
Credit facility maturity date	24-Jun-19
Quarterly amortization payments on term loan as a percentage of aggregate principal amount	1.25%
Commitment fee on unused portions of credit agreement, variable range	0.23%
Credit facility, aggregate borrowings outstanding	300,000,000	447,000
Aggregate amount borrowed by issuing letters of credit	11,000,000
Aggregate value of bank guarantees	101,500,000
Bonds issued and outstanding	437,900,000
Minimum [Member]
Debt Instrument [Line Items]
Commitment fee on unused portions of credit agreement, variable range	0.20%
Maximum [Member]
Debt Instrument [Line Items]
Commitment fee on unused portions of credit agreement, variable range	0.35%
Financial Letter of Credit [Member]
Debt Instrument [Line Items]
Letter of credit fee on unused portions of credit agreement, variable range	1.38%
Financial Letter of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Letter of credit fee on unused portions of credit agreement, variable range	1.25%
Financial Letter of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Letter of credit fee on unused portions of credit agreement, variable range	2.00%
Performance Letter Of Credit [Member]
Debt Instrument [Line Items]
Letter of credit fee on unused portions of credit agreement, variable range	0.80%
Performance Letter Of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Letter of credit fee on unused portions of credit agreement, variable range	0.73%
Performance Letter Of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Letter of credit fee on unused portions of credit agreement, variable range	1.13%
Eurodollar-Rate Loans [Member]
Debt Instrument [Line Items]
Annual interest rate of loan outstanding under credit agreement	1.25%
Annual interest rate of loan outstanding under credit agreement	2.00%
Annual interest rate of loan outstanding under credit agreement	1.38%
Base-Rate Loans [Member]
Debt Instrument [Line Items]
Annual interest rate of loan outstanding under credit agreement	0.25%
Annual interest rate of loan outstanding under credit agreement	1.00%
Annual interest rate of loan outstanding under credit agreement	0.38%
Base-Rate Loans [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Annual interest rate of loan outstanding under credit agreement	0.50%
Base-Rate Loans [Member] | 30-Day Eurodollar Rate [Member]
Debt Instrument [Line Items]
Annual interest rate of loan outstanding under credit agreement	1.00%
Letter of Credit [Member]
Debt Instrument [Line Items]
Credit agreement, maximum borrowing capacity			1,000,000,000
Aggregate amount borrowed by issuing letters of credit	171,900,000
Aggregate amount to be borrowed to meet letter of credit requirements	828,100,000
Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Credit agreement, maximum borrowing capacity			300,000,000
Incremental term loan, maximum capacity			400,000,000
Credit facility, aggregate borrowings outstanding	$300,000,000
Term Loan [Member]
Debt Instrument [Line Items]
Interest rate on term loan borrowings	1.54%

Pension_Plans_and_Postretireme2

Pension Plans and Postretirement Benefits - Obligations and Funded Status (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Actuarial loss (gain)	$241,627	($222,925)	$32,040
Fair value of plan assets at beginning of period	2,224,597
Fair value of plan assets at the end of period	2,386,195	2,224,597
Accumulated postretirement benefit obligation	-58,213	-43,194
Pension liability	-563,990	-336,878
Pension Benefits Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Benefit obligation at beginning of period	2,570,095	2,779,990
Service cost	37,878	46,417	46,828
Interest cost	119,368	111,200	122,605
Plan participants' contributions	264	266
Curtailments	772
Amendments	305	3,105
Acquisition	5,108
Settlements	-23,339	-21,862
Actuarial loss (gain)	366,146	-195,290
Foreign currency exchange rate changes	-20,709	-17,465
Benefits paid	-146,900	-136,266
Benefit obligation at end of period	2,908,988	2,570,095	2,779,990
Fair value of plan assets at beginning of period	2,181,323	2,127,694
Actual return on plan assets	288,630	155,071
Plan participants' contributions	264	266
Company contributions	63,649	70,681
Settlements	-23,339	-21,862
Foreign currency exchange rate changes	-19,183	-14,261
Benefits paid	-146,900	-136,266
Fair value of plan assets at the end of period	2,344,444	2,181,323	2,127,694
Funded status	-564,544	-388,772
Accrued employee benefits	-4,051	-54,391
Pension liability	-562,176	-334,538
Prepaid pension	1,683	157
Accrued benefit liability, net	-564,544	-388,772
Prior service cost (credit)	14,204	18,237
Projected benefit obligation	2,789,053	2,433,369
Accumulated benefit obligation	2,770,436	2,406,269
Fair value of plan assets	2,222,825	2,047,507
Projected benefit obligation	119,935	136,726
Accumulated benefit obligation	117,503	132,221
Fair value of plan assets	121,619	133,816
Postretirement Benefit Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Benefit obligation at beginning of period	95,906	116,256
Service cost	777	975	1,138
Interest cost	3,827	3,745	5,124
Plan participants' contributions	1,546	1,055
Actuarial loss (gain)	12,974	-16,335
Foreign currency exchange rate changes	-691	-655
Benefits paid	-7,902	-9,135
Benefit obligation at end of period	106,437	95,906	116,256
Fair value of plan assets at beginning of period	43,274	37,324
Actual return on plan assets	-415	6,056
Plan participants' contributions	1,546	1,055
Company contributions	5,248	7,974
Benefits paid	-7,902	-9,135
Fair value of plan assets at the end of period	41,751	43,274	37,324
Funded status	-64,686	-52,632
Accrued employee benefits	-6,473	-9,438
Accumulated postretirement benefit obligation	-58,213	-43,194
Accrued benefit liability, net	-64,686	-52,632
Prior service cost (credit)	-2,181	-2,338
Accumulated benefit obligation	106,437	95,906
Fair value of plan assets	$41,751	$43,274

Pension_Plans_and_Postretireme3

Pension Plans and Postretirement Benefits - Components of Net Periodic Benefit Cost (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$37,878	$46,417	$46,828
Interest cost	119,368	111,200	122,605
Expected return on plan assets	-149,231	-147,621	-136,913
Amortization of prior service cost	2,672	3,158	3,579
Recognized net actuarial loss (gain)	229,053	-202,442	34,496
Net periodic benefit cost (income)	239,740	-189,288	70,595
Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	777	975	1,138
Interest cost	3,827	3,745	5,124
Expected return on plan assets	-2,295	-2,116	-1,930
Amortization of prior service cost	-163	-148	-139
Recognized net actuarial loss (gain)	12,574	-20,483	-2,456
Net periodic benefit cost (income)	$14,720	($18,027)	$1,737

Pension_Plans_and_Postretireme4

Pension Plans and Postretirement Benefits - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Increase in pension liability	$117.70
Other comprehensive loss as components of net periodic benefit cost for pension benefit in the current fiscal year	2.7
Other comprehensive loss as components of net periodic benefit cost for other benefit in the current fiscal year	-0.2
Other comprehensive loss as components of net periodic benefit cost for pension benefit in the next fiscal year	2.2
Other comprehensive loss as components of net periodic benefit cost for other benefit in the next fiscal year	-0.2
Expected return on plan assets	7.20%
Percentage of investment return on domestic plan assets	14.00%	7.00%
Term of written notice required for termination from plan (in days)	90 days
Contributions as a percentage of total contributions to the Boilermaker Plan	5.00%
SERP Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	0.5	0.7	0.6
Pension Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	7.00%	7.06%
Percentage of total assets	90.00%
Voluntary Employees' Beneficiary Association Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of total assets	87.00%
Thrift Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of matching contribution by employer	50.00%
Thrift Plan [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Participants' contributions as a percentage of compensation	6.00%
Thrift Plan and MII Thrift Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	25.5	24.3	24.2
Restoration Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	0.2	0.2	0.1
Canadian Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$0.60	$0.60	$0.50

Pension_Plans_and_Postretireme5

Pension Plans and Postretirement Benefits - Recognized Net Actuarial Loss (Gain) and the Affected Consolidated Statements of Income (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Mark to Market Adjustment	$241,627	($222,925)	$32,040
Cost of Operations [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Mark to Market Adjustment	223,269	-191,352	23,893
Selling, General and Administrative Expenses [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Mark to Market Adjustment	17,887	-31,384	7,997
Other-net [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Mark to Market Adjustment	$471	($189)	$150

Pension_Plans_and_Postretireme6

Pension Plans and Postretirement Benefits - Summary of Additional Information (Detail) (Pension Benefits Plan [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Increase (decrease) in accumulated other comprehensive income due to actuarial losses - before taxes	($1,351)	($3,105)

Pension_Plans_and_Postretireme7

Pension Plans and Postretirement Benefits - Weighted Average Assumptions (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Weighted average assumptions used to determine net periodic benefit cost, Expected return on plan assets	7.20%
Pension Benefits Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Weighted average assumptions used to determine net periodic benefit obligations, Discount rate	3.99%	4.78%
Weighted average assumptions used to determine net periodic benefit obligations, Rate of compensation increase	2.57%	2.56%
Weighted average assumptions used to determine net periodic benefit cost, Discount rate	4.78%	4.09%
Weighted average assumptions used to determine net periodic benefit cost, Expected return on plan assets	7.00%	7.06%
Weighted average assumptions used to determine net periodic benefit cost, Rate of compensation increase	2.56%	2.57%
Postretirement Benefit Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Weighted average assumptions used to determine net periodic benefit obligations, Discount rate	3.74%	4.23%
Weighted average assumptions used to determine net periodic benefit cost, Discount rate	4.23%	3.43%
Weighted average assumptions used to determine net periodic benefit cost, Expected return on plan assets	5.73%	5.74%

Pension_Plans_and_Postretireme8

Pension Plans and Postretirement Benefits - Assumed Health Care Cost Trend Rates (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Health-care cost trend rate assumed for next year	7.50%	8.00%
Rates to which the cost trend rate is assumed to decline (ultimate trend rate)	4.50%	4.50%
Year that the rate reaches ultimate trend rate	2021	2021

Pension_Plans_and_Postretireme9

Pension Plans and Postretirement Benefits - Effect of One Percentage Point Change in Assumed Health Care Cost Trend Rates (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
One-Percentage-Point Increase, Effect on total of service and interest cost	$425
One-Percentage-Point Increase, Effect on postretirement benefit obligation	8,802
One-Percentage-Point Decrease, Effect on total of service and interest cost	-331
One-Percentage-Point Decrease, Effect on postretirement benefit obligation	($7,400)

Recovered_Sheet9

Pension Plans and Postretirement Benefits - Plan Asset Allocations by Asset Category (Detail)	Dec. 31, 2014	Dec. 31, 2013
Domestic Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	100.00%	100.00%
Domestic Plans [Member] | Fixed Income (Excluding U. S. Government Securities) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	38.00%	30.00%
Domestic Plans [Member] | Commingled and Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	3300.00%	3600.00%
Domestic Plans [Member] | U.S. Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	15.00%	18.00%
Domestic Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	7.00%	7.00%
Domestic Plans [Member] | Partnerships with Security Holdings [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	5.00%	6.00%
Domestic Plans [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	1.00%	1.00%
Domestic Plans [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	1.00%	2.00%
Foreign Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	100.00%	100.00%
Foreign Plans [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	2.00%	3.00%
Foreign Plans [Member] | Equity Securities and Commingled Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	55.00%	58.00%
Foreign Plans [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	43.00%	39.00%

Recovered_Sheet10

Pension Plans and Postretirement Benefits - Target Allocation by Asset Class (Detail)	12 Months Ended
	Dec. 31, 2014
Domestic Plans [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	55.00%
Domestic Plans [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	45.00%
Canadian Plans [Member] | Scenario, Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	45.00%
Canadian Plans [Member] | Scenario, Plan [Member] | U. S. Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	17.00%
Canadian Plans [Member] | Scenario, Plan [Member] | Global Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	38.00%
Diamond UK Plan [Member] | Scenario, Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	73.00%
Diamond UK Plan [Member] | Scenario, Plan [Member] | U. S. Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	12.00%
Diamond UK Plan [Member] | Scenario, Plan [Member] | Global Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	15.00%

Recovered_Sheet11

Pension Plans and Postretirement Benefits - Summary of Total Investments Measured at Fair Value (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	$2,386,195	$2,224,597
Fixed Income [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	907,046	682,028
Equities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	141,471	144,438
Commingled and Mutual Funds [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	839,472	861,354
U.S. Government Securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	324,169	355,245
Partnerships with Security Holdings [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	110,565	116,154
Real Estate [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	4,831	6,214
Cash and Accrued Items [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	58,641	59,164
Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	526,890	578,853
Level 1 [Member] | Equities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	141,471	144,438
Level 1 [Member] | Commingled and Mutual Funds [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	24,852	31,083
Level 1 [Member] | U.S. Government Securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	308,867	355,245
Level 1 [Member] | Cash and Accrued Items [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	51,700	48,087
Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	1,743,909	1,523,376
Level 2 [Member] | Fixed Income [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	907,046	682,028
Level 2 [Member] | Commingled and Mutual Funds [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	814,620	830,271
Level 2 [Member] | U.S. Government Securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	15,302
Level 2 [Member] | Cash and Accrued Items [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	6,941	11,077
Level 3 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	115,396	122,368	127,400
Level 3 [Member] | Partnerships with Security Holdings [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	110,565	116,154
Level 3 [Member] | Real Estate [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total Assets	$4,831	$6,214

Recovered_Sheet12

Pension Plans and Postretirement Benefits - Summary of Changes in Plans Level 3 Instruments Measured on Recurring Basis (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at the end of period	$2,386,195	$2,224,597
Level 3 [Member]
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of period	122,368	127,400
Issuances and acquisitions	10,387	6,016
Dispositions	-34,471	-31,471
Realized gain	24,835	18,058
Unrealized gain	-7,723	2,365
Fair value of plan assets at the end of period	$115,396	$122,368

Recovered_Sheet13

Pension Plans and Postretirement Benefits - Cash Flows (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Domestic Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Expected employer contributions to trusts of defined benefit plans, 2015	$330
Expected benefit payments, 2015	140,258
Expected benefit payments, 2016	145,703
Expected benefit payments, 2017	150,335
Expected benefit payments, 2018	154,417
Expected benefit payments, 2019	157,714
Expected benefit payments, 2020-2024	813,034
Domestic Plans, Other Benefits [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Expected employer contributions to trusts of defined benefit plans, 2015	2,271
Expected benefit payments, 2015	8,245
Expected benefit payments, 2016	7,832
Expected benefit payments, 2017	7,428
Expected benefit payments, 2018	7,258
Expected benefit payments, 2019	7,233
Expected benefit payments, 2020-2024	32,172
Foreign Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Expected employer contributions to trusts of defined benefit plans, 2015	14,618
Expected benefit payments, 2015	10,538
Expected benefit payments, 2016	10,832
Expected benefit payments, 2017	11,144
Expected benefit payments, 2018	11,536
Expected benefit payments, 2019	11,909
Expected benefit payments, 2020-2024	64,854
Foreign Plans, Other Benefits [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Expected benefit payments, 2015	513
Expected benefit payments, 2016	501
Expected benefit payments, 2017	519
Expected benefit payments, 2018	544
Expected benefit payments, 2019	545
Expected benefit payments, 2020-2024	$2,873

Recovered_Sheet14

Pension Plans and Postretirement Benefits - Summary of Contribution to Multiemployer Plans (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Multiemployer Plans [Line Items]
Contributions	$20.60	$30.90	$24.20
Boilermaker-Blacksmith National Pension Trust [Member]
Multiemployer Plans [Line Items]
EIN/PIN	48-6168020/ 001
Pension Protection Act Zone Zone Status	Yellow	Yellow
FIP/RP Status Pending/Implemented	Yes
Contributions	16	19	18.9
Surcharge Imposed	No
All Other [Member]
Multiemployer Plans [Line Items]
Contributions	$4.60	$11.90	$5.30

Capital_Stock_Additional_Infor

Capital Stock - Additional Information (Detail) (USD $)	0 Months Ended		1 Months Ended	12 Months Ended
	Feb. 26, 2014	Dec. 09, 2013	31-May-13	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2012
Equity [Abstract]
Common stock at an aggregate purchase price							$250,000,000
Additional common stock at an aggregate purchase price	250,000,000		250,000,000
Common stock repurchased		$250,000,000		$149,700,000	$157,000,000	$96,700,000
Common stock repurchased, expiration date				25-Feb-16
Common stock repurchased, shares				4,687,500	5,620,690	3,908,684

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended				3 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010	Jun. 30, 2012	Aug. 13, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Actual tax benefits realized related to the stock options exercised	$3.30
B&W Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value of options granted	$7.03	$6.41	$7.30
Total intrinsic value of stock options exercised	2.1	2.3	3.8
Actual tax benefits realized related to the stock options exercised	0.8
B&W Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average vested shares	56.00%
Vesting period	3 years
B&W Performance Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares in which participants can vest	0.00%
B&W Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares in which participants can vest	200.00%
Stock Appreciation Right [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value of options granted	$3.21	$3.95	$4.16
Cash Settled Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average vested shares	58.00%
Vesting period	3 years
B&W Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Actual tax benefits realized related to the stock options exercised	2.3
2010 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance				10,000,000
Additional shares authorized for issuance	2,300,000
Minimum percentage of fair market value closing price				100.00%
Expiry date of B&W common stock				7 years
Shares issued under the plan	7,179,441
Shares available for issuance of awards in future	5,120,559
2012 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum percentage of fair market value closing price					100.00%
Expiry date of B&W common stock					7 years
Total unrecognized estimated compensation expense, nonvested awards	24.5
Unrecognized estimated compensation expense to be recognized, weighted-average period	1 year 10 months 24 days
MII Legacy Stock-Based Compensation Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	9.8	16.5	18.3
Stock-based compensation, tax benefits	$3.20	$6.20	$6.90
Thrift Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance						5,000,000
Shares issued under the plan	436,246
Shares available for issuance of awards in future	2,820,973
Vesting period						3 years
Percentage of matching contribution by employer						50.00%
Thrift Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Participants contributions as a percentage of compensation						6.00%

StockBased_Compensation_Schedu

Stock-Based Compensation - Schedule of Assumptions Used to Calculate Fair Value of Option Grant (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
B&W Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.97%	0.56%	0.65%
Expected volatility	0.30%	0.33%	0.36%
Expected life of the option in years	3 years 9 months 4 days	3 years 11 months 5 days	3 years 11 months 23 days
Expected dividend yield	1.22%	1.19%	0.00%
Cash-Settled Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.12%	0.77%	0.50%
Expected volatility	0.25%	0.30%	0.32%
Expected life of the option in years	3 years 2 months 16 days	3 years 2 months 16 days	3 years 6 months 18 days
Expected dividend yield	1.42%	1.19%	1.23%

StockBased_Compensation_Summar

Stock-Based Compensation - Summarized Activity of Stock Options (Detail) (B&W Stock Options [Member], USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014
B&W Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of period, Number of Shares	1,974,000
Granted, Number of Shares	943,000
Exercised, Number of Shares	-194,000
Cancelled/expired/forfeited, Number of Shares	-176,000
Outstanding at end of period, Number of Shares	2,547,000
Exercisable at end of period, Number of Shares	989,000
Outstanding at beginning of period, Weighted-Average Exercise Price	$26.87
Granted, Weighted-Average Exercise Price	$32.66
Exercised, Weighted-Average Exercise Price	$21.50
Cancelled/expired/forfeited, Weighted-Average Exercise Price	$30.88
Outstanding at end of period, Weighted-Average Exercise Price	$29.15
Exercisable at end of period, Weighted-Average Exercise Price	$27.76
Outstanding at end of period, Weighted-Average Remaining Contractual Term	4 years 10 months 24 days
Exercisable at end of period, Weighted-Average Remaining Contractual Term	3 years 8 months 12 days
Outstanding at end of period, Aggregate Intrinsic Value	$6.30
Exercisable at end of period, Aggregate Intrinsic Value	$3.80

StockBased_Compensation_Schedu1

Stock-Based Compensation - Schedule of Changes in Nonvested Stock Awards (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
B&W Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at beginning of period, Number of Shares	834
Adjustment to assumed vesting percentage, Number of Shares	-294
Granted, Number of Shares	365
Vested, Number of Shares	-270
Cancelled/forfeited, Number of Shares	-100
Nonvested at end of period, Number of Shares	535
Nonvested at beginning of period, Weighted-Average Grant Date Fair Value	$29.07
Adjustment to assumed vesting percentage, Weighted-Average Grant Date Fair Value	$27.38
Granted, Weighted-Average Grant Date Fair Value	$32.79
Vested, Weighted-Average Grant Date Fair Value	$32.77
Cancelled/forfeited, Weighted-Average Grant Date Fair Value	$29.38
Nonvested at end of period, Weighted-Average Grant Date Fair Value	$30.64
B&W Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at beginning of period, Number of Shares	385
Granted, Number of Shares	225
Vested, Number of Shares	-206
Cancelled/forfeited, Number of Shares	-28
Nonvested at end of period, Number of Shares	376
Nonvested at beginning of period, Weighted-Average Grant Date Fair Value	$26.78
Granted, Weighted-Average Grant Date Fair Value	$32.84
Vested, Weighted-Average Grant Date Fair Value	$28.43
Cancelled/forfeited, Weighted-Average Grant Date Fair Value	$29.02
Nonvested at end of period, Weighted-Average Grant Date Fair Value	$29.33

StockBased_Compensation_Schedu2

Stock-Based Compensation - Schedule of Summarized Activity of Stock Appreciation (Detail) (Stock Appreciation Right [Member], USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014
Stock Appreciation Right [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of period, Number of Shares	96,000
Granted, Number of Units	66,000
Exercised, Number of Units	-15,000
Cancelled/expired/forfeited, Number of Units	-44,000
Outstanding at end of period, Number of Shares	103,000
Exercisable at end of period, Number of Shares	40,000
Outstanding at beginning of period, Weighted-Average Exercise Price	$26.35
Granted, Weighted-Average Exercise Price	$32.69
Exercised, Weighted-Average Exercise Price	$26.07
Cancelled/expired/forfeited, Weighted-Average Exercise Price	$30.28
Outstanding at end of period, Weighted-Average Exercise Price	$28.72
Exercisable at end of period, Weighted-Average Exercise Price	$26.35
Outstanding at end of period, Weighted-Average Remaining Contractual Term	5 years 4 months 24 days
Exercisable at end of period, Weighted-Average Remaining Contractual Term	5 years
Outstanding at end of period, Aggregate Intrinsic Value	$0.30
Exercisable at end of period, Aggregate Intrinsic Value	$0.20

StockBased_Compensation_Schedu3

Stock-Based Compensation - Schedule of Nonvested Cash Settled Performance Units (Detail) (Cash Settled Performance Units [Member], USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Cash Settled Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at beginning of period, Number of Shares	51
Adjustment to assumed vesting percentage	-21
Granted, Number of Units	34
Vested, Number of Units	0
Cancelled/forfeited, Number of Units	-27
Nonvested at end of period, Number of Shares	37
Nonvested at end of period, Weighted-Average Fair Value	$30.30

StockBased_Compensation_Schedu4

Stock-Based Compensation - Schedule of Nonvested Cash Settled Restricted Stock Units (Detail) (Cash Settled Restricted Stock Units [Member])	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Cash Settled Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at beginning of period, Number of Shares	23
Granted, Number of Units	12
Vested, Number of Units	-13
Cancelled/forfeited, Number of Units	-9
Nonvested at end of period, Number of Shares	13

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

Jan. 16, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Aug. 29, 2014

Dec. 17, 2014

Nov. 12, 2014

Nov. 30, 2014

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 1998

Feb. 14, 2012

LetterOfCredit

Venture

Contingencies And Commitments [Line Items]

Interest rate on settlement

6.00%

Appeal bond required as a percentage of total judgment

120.00%

Number of partial draws

9

Total partial draws under letter of credit outstanding

$11,000,000

Total draws of Letter of Credit in LDs

11,900,000

Outstanding letter of credit

11,000,000

Damages in excess

37,000,000

Letters of credit remaining amount

21,900,000

Number of joint ventures

2

Total rental expense

12,500,000

11,600,000

12,100,000

Nuclear Waste Partnership, LLC [Member]

Contingencies And Commitments [Line Items]

Interest in joint venture

30.00%

Los Alamos National Security, LLC [Member]

Contingencies And Commitments [Line Items]

Interest in joint venture

13.00%

New Hampshire suit [Member] | Minimum [Member]

Contingencies And Commitments [Line Items]

Recovery of damages incurred

66,000,000

DOE and NWP [Member]

Contingencies And Commitments [Line Items]

Civil penalties

17,750,000

DOE and LANS [Member]

Contingencies And Commitments [Line Items]

Civil penalties

36,600,000

AREVA NP, INC. f/k/a Framatome ANP, Inc [Member]

Contingencies And Commitments [Line Items]

Civil penalties

16,000,000

Prairie Island [Member]

Contingencies And Commitments [Line Items]

Recovery of damages incurred

45,400,000

Apollo and Parks Township [Member]

Contingencies And Commitments [Line Items]

Number of claimants

94

Number of facilities

2

Number of cases consolidated for most non-dispositive pre-trial matters

16

Recovery of damages incurred

125,000,000

Aggregate settlement amount for claims

52,500,000

27,500,000

8,000,000

Percentage of ARCO's recovery amounts assigned to company

58.33%

Apollo and Parks Township [Member] | Personal Injury and Wrongful Death Claims [Member]

Contingencies And Commitments [Line Items]

Number of claims settled

250

Apollo and Parks Township [Member] | Property Damage Claims [Member]

Contingencies And Commitments [Line Items]

Number of claims settled

125

Apollo and Parks Township [Member] | 2008 Settlement [Member]

Contingencies And Commitments [Line Items]

Interest accrued on settlement

8,800,000

Apollo and Parks Township [Member] | 2009 Settlement [Member]

Contingencies And Commitments [Line Items]

Interest accrued on settlement

6,200,000

Environmental Matters [Member]

Contingencies And Commitments [Line Items]

Financial assurance to pay expected cost of decommissioning

44,200,000

Number of facilities

2

Pretax charge to comply U.S. federal, state and local environmental control and protection regulations

13,600,000

Capital expenditure to comply environmental regulations

300,000

Environmental reserves

59,900,000

58,100,000

Environmental reserves included in current liabilities

$3,600,000

$4,700,000

Commitments_and_Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Payments for Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2015	$9,896
2016	7,049
2017	6,067
2018	4,956
2019	3,489
Thereafter	$1,221

Financial_Instruments_with_Con1

Financial Instruments with Concentrations of Credit Risk - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Allowance for possible losses on accounts receivable - trade	13.7	3.6
Government Contracts Concentration Risk [Member] | Sales Revenue, Net [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk percentage	45.00%	38.00%	34.00%
Government Contracts Concentration Risk [Member] | Accounts Receivable [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk percentage	25.00%	20.00%

Investments_Summary_of_Availab

Investments - Summary of Available for Sale Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$12,390	$14,971
Gross Unrealized Gains	293	258
Gross Unrealized Losses	-240	-55
Estimated Fair Value	12,443	15,174
Corporate Bonds [Member] | Centrus Energy Corp. [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,628
Gross Unrealized Losses	-189
Estimated Fair Value	2,439
Equities [Member] | Centrus Energy Corp. [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,088
Estimated Fair Value	3,088
Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,906	3,752
Gross Unrealized Gains	293	249
Estimated Fair Value	4,199	4,001
Asset-Backed Securities and Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	370	472
Gross Unrealized Gains		8
Gross Unrealized Losses	-51	-55
Estimated Fair Value	319	425
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,398	7,748
Estimated Fair Value	2,398	7,748
U.S. Government and Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,999
Gross Unrealized Gains		1
Estimated Fair Value		$3,000

Investments_Summary_of_Proceed

Investments - Summary of Proceeds, Gross Realized Gains and Gross Realized Losses on Sales of Available for Sale Securities (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortized Cost and Fair Value Debt Securities [Abstract]
Proceeds	$32,089	$168,879	$247,649
Gross Realized Gains	172	1,127	35
Gross Realized Losses	$0	$0	$0

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Schedule of Effect of Derivative Instruments on Statements of Financial Performance (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Net gains deferred on derivative financial instruments in accumulated other comprehensive loss	$100,000
Notional amount of foreign currency forward	74,200,000
Maturity date of foreign currency contracts	Dec-16
Derivatives Designated as Hedges [Member] | Cash Flow Hedges [Member] | FX Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of loss recognized in other comprehensive income	-3,184,000	-5,936,000
Derivatives Designated as Hedges [Member] | Cash Flow Hedges [Member] | FX Forward Contracts [Member] | Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified from accumulated other comprehensive income into earnings: effective portion	620,000	-1,885,000
Derivatives Designated as Hedges [Member] | Cash Flow Hedges [Member] | FX Forward Contracts [Member] | Cost of Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified from accumulated other comprehensive income into earnings: effective portion	-2,793,000	-2,174,000
Derivatives Designated as Hedges [Member] | Cash Flow Hedges [Member] | FX Forward Contracts [Member] | Other-Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified from accumulated other comprehensive income into earnings: effective portion	4,000	144,000
Loss recognized in income: portion excluded from effectiveness testing	-104,000	-349,000
Derivatives Not Designated as Hedges [Member] | Forward Contracts [Member] | Other-Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in income	($184,000)	$96,000

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Summary of Derivative Financial Instruments (Detail) (FX Forward Contracts [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives Designated as Hedges [Member] | Accounts Receivable-Other [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$541	$1,139
Derivatives Designated as Hedges [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives		94
Derivatives Designated as Hedges [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	743	603
Derivatives Designated as Hedges [Member] | Accounts Payable [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	2,744	581
Derivatives Not Designated as Hedges [Member] | Accounts Receivable-Other [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	176	464
Derivatives Not Designated as Hedges [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives		50
Derivatives Not Designated as Hedges [Member] | Accounts Payable [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	$284	$10

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	12 Months Ended		3 Months Ended	0 Months Ended	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013	Sep. 05, 2014	Dec. 31, 2014	Dec. 31, 2012	Sep. 30, 2014
Fair Values Of Financial Instruments [Line Items]
Net unrealized gain on investments	$0.10	$0.20
FX Forward Contracts [Member]
Fair Values Of Financial Instruments [Line Items]
Fair value of foreign currency forward contracts	3.1	0.6	0.6		3.1
USEC, Inc. Investment [Member]
Fair Values Of Financial Instruments [Line Items]
Impairment of investment			19.1
Reorganization [Member]
Fair Values Of Financial Instruments [Line Items]
Percentage of ownership received				7.98%
Principal amount of notes				20.2
Convertible preferred stock and warrants (interest rate)				12.75%
Fair value of common stock and notes							18.6
Reorganization [Member] | Centrus Energy Corp. [Member]
Fair Values Of Financial Instruments [Line Items]
Other than temporary impairment					4.2
Reorganization [Member] | USEC, Inc. Investment [Member]
Fair Values Of Financial Instruments [Line Items]
Impairment of investment		19.1				27
Letter of Credit [Member]
Fair Values Of Financial Instruments [Line Items]
Guarantee, issued a letter of credit	10				10
Guarantee, term of letter of credit	four year term
Fair value of guarantee recognised	$1.70				$1.70
PIK Toggle Notes Due 2019/2024 [Member] | Reorganization [Member]
Fair Values Of Financial Instruments [Line Items]
Percentage of debt instrument interest rate				8.00%

Fair_Value_Measurements_Summar

Fair Value Measurements - Summary of Investments and Available-for-Sale Securities Measured at Fair Value (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	$12,443	$15,174
Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	3,088
Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	4,199	4,001
U.S. Government and Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value		3,000
Asset-Backed Securities and Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	319	425
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	2,398	7,748
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities measure at fair value	2,439
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	2,439	3,000
Level 1 [Member] | U.S. Government and Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value		3,000
Level 1 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities measure at fair value	2,439
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	10,004	12,174
Level 2 [Member] | Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	3,088
Level 2 [Member] | Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	4,199	4,001
Level 2 [Member] | Asset-Backed Securities and Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	319	425
Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities measured at fair value	$2,398	$7,748

Segment_Reporting_Schedule_of_

Segment Reporting - Schedule of Operating Results by Segment (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues	$837,094	$737,902	$686,006	$662,017	$802,815	$774,834	$886,136	$805,423	$2,923,019	$3,269,208	$3,291,359
Special Charges for Restructuring Activities									-41,091	-39,599
Mark to Market Adjustment									-241,156	222,737	-31,890
Operating income	-156,540	65,160	35,118	53,640	295,322	82,121	98,706	60,213	-2,622	536,362	346,589
Interest income									1,028	1,443	1,491
Interest expense									-7,579	-3,115	-3,735
Other - net									14,639	-17,517	-24,927
Total Other Income (Expense)									8,088	-19,189	-27,171
Income before Provision for Income Taxes									5,466	517,173	319,418
Losses (gains) on asset disposals and impairments									1,081	1,049	1,419
Equity in Income of Investees	5,996	7,308	13,183	15,269	16,345	18,151	18,775	14,787	41,756	68,058	66,709
Power Generation [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									1,486,029	1,767,651	1,785,959
Losses (gains) on asset disposals and impairments									1,752	1,181	3,276
Equity in Income of Investees									8,682	18,388	17,402
Nuclear Operations [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									1,220,952	1,167,683	1,098,031
Losses (gains) on asset disposals and impairments										163	-339
Equity in Income of Investees									0	0	0
Technical Services [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									84,834	104,254	107,851
Losses (gains) on asset disposals and impairments											-1,517
Equity in Income of Investees									33,042	50,281	49,621
Nuclear Energy [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									154,721	283,857	325,655
Losses (gains) on asset disposals and impairments									-665	-28	-1
Equity in Income of Investees									32	-611	-314
mPower [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									278	1,523	326
Losses (gains) on asset disposals and impairments									0	0	0
Equity in Income of Investees									0	0	0
Corporate [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Losses (gains) on asset disposals and impairments									-6	-267
Operating Segments [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Operating income									312,139	379,263	406,432
Operating Segments [Member] | Power Generation [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									1,486,029	1,767,651	1,785,959
Operating income									98,557	155,837	183,387
Operating Segments [Member] | Nuclear Operations [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									1,220,952	1,167,683	1,098,031
Operating income									270,536	237,855	226,269
Operating Segments [Member] | Technical Services [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									84,834	104,254	107,851
Operating income									35,203	58,234	59,655
Operating Segments [Member] | Nuclear Energy [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									154,721	283,857	325,655
Operating income									-23,211	8,641	50,649
Operating Segments [Member] | mPower [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									278	1,523	326
Operating income									-68,946	-81,304	-113,528
Adjustments and Eliminations [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									-23,795	-55,760	-26,463
Adjustments and Eliminations [Member] | Power Generation [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									-5,896	-37,552	-7,932
Adjustments and Eliminations [Member] | Nuclear Operations [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									-9,922	-6,773	-6,015
Adjustments and Eliminations [Member] | Technical Services [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									-57	-3,817	-3,496
Adjustments and Eliminations [Member] | Nuclear Energy [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues									-7,920	-7,618	-8,992
Adjustments and Eliminations [Member] | mPower [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Revenues											-28
Unallocated Corporate [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Operating income									($32,514)	($26,039)	($27,953)

Segment_Reporting_Schedule_of_1

Segment Reporting - Schedule of Segment Reporting Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total Assets	$2,856,936	$2,609,153	$2,840,355
Total Capital Expenditures	76,029	64,950	86,635
Total Depreciation and Amortization	105,798	70,525	69,697
Total Investment in Unconsolidated Affiliates	140,504	184,831	186,354
Power Generation [Member]
Segment Reporting Information [Line Items]
Total Assets	1,018,149	970,718	1,059,824
Total Capital Expenditures	15,449	15,280	24,592
Total Depreciation and Amortization	30,661	23,892	19,126
Total Investment in Unconsolidated Affiliates	109,248	144,475	139,399
Nuclear Operations [Member]
Segment Reporting Information [Line Items]
Total Assets	770,359	778,203	708,607
Total Capital Expenditures	34,777	31,572	44,810
Total Depreciation and Amortization	54,524	26,975	32,013
Total Investment in Unconsolidated Affiliates	0	0	0
Technical Services [Member]
Segment Reporting Information [Line Items]
Total Assets	114,581	120,559	125,494
Total Capital Expenditures	66	98
Total Depreciation and Amortization	3	185	244
Total Investment in Unconsolidated Affiliates	31,229	40,329	46,928
Nuclear Energy [Member]
Segment Reporting Information [Line Items]
Total Assets	427,412	439,325	391,096
Total Capital Expenditures	14,358	5,506	5,881
Total Depreciation and Amortization	6,564	6,520	5,923
Total Investment in Unconsolidated Affiliates	27	27	27
mPower [Member]
Segment Reporting Information [Line Items]
Total Assets	17,233	21,790	10,137
Total Capital Expenditures	1,983	2,854	2,554
Total Depreciation and Amortization	974	554	279
Total Investment in Unconsolidated Affiliates	0	0	0
Corporate [Member]
Segment Reporting Information [Line Items]
Total Assets	509,202	278,558	545,197
Total Capital Expenditures	9,396	9,640	8,798
Total Depreciation and Amortization	13,072	12,399	12,112
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Assets	2,347,734	2,330,595	2,295,158
Total Capital Expenditures	66,633	55,310	77,837
Total Depreciation and Amortization	$92,726	$58,126	$57,585

Segment_Reporting_Schedule_of_2

Segment Reporting - Schedule of Revenue Information from Products and Service Lines (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue from External Customer [Line Items]
Revenues	$837,094	$737,902	$686,006	$662,017	$802,815	$774,834	$886,136	$805,423	$2,923,019	$3,269,208	$3,291,359
Adjustments and Eliminations [Member]
Revenue from External Customer [Line Items]
Revenues									-23,795	-55,760	-26,463
Power Generation [Member]
Revenue from External Customer [Line Items]
Revenues									1,486,029	1,767,651	1,785,959
Power Generation [Member] | New Build Environmental Equipment [Member]
Revenue from External Customer [Line Items]
Revenues									234,475	434,228	446,514
Power Generation [Member] | New Build Steam Generation Systems [Member]
Revenue from External Customer [Line Items]
Revenues									358,539	454,277	511,201
Power Generation [Member] | Aftermarket Services [Member]
Revenue from External Customer [Line Items]
Revenues									796,061	885,185	841,571
Power Generation [Member] | Industrial Environmental [Member]
Revenue from External Customer [Line Items]
Revenues									105,400
Power Generation [Member] | Adjustments and Eliminations [Member]
Revenue from External Customer [Line Items]
Revenues									-8,446	-6,039	-13,327
Nuclear Operations [Member]
Revenue from External Customer [Line Items]
Revenues									1,220,952	1,167,683	1,098,031
Nuclear Operations [Member] | Adjustments and Eliminations [Member]
Revenue from External Customer [Line Items]
Revenues									11,674	6,786	6,042
Nuclear Operations [Member] | Nuclear Component Program [Member]
Revenue from External Customer [Line Items]
Revenues									1,208,505	1,153,216	1,086,081
Nuclear Operations [Member] | Commercial Operations [Member]
Revenue from External Customer [Line Items]
Revenues									773	7,681	5,908
Technical Services [Member]
Revenue from External Customer [Line Items]
Revenues									84,834	104,254	107,851
Technical Services [Member] | Commercial Operations [Member]
Revenue from External Customer [Line Items]
Revenues									10,897	21,227	20,819
Technical Services [Member] | Nuclear Environmental Services [Member]
Revenue from External Customer [Line Items]
Revenues									70,998	73,043	78,228
Technical Services [Member] | Management & Operation Contracts Of U.S. Government Facilities [Member]
Revenue from External Customer [Line Items]
Revenues									2,939	9,984	8,804
Nuclear Energy [Member]
Revenue from External Customer [Line Items]
Revenues									154,721	283,857	325,655
Nuclear Energy [Member] | Adjustments and Eliminations [Member]
Revenue from External Customer [Line Items]
Revenues										226	-40
Nuclear Energy [Member] | Nuclear Services [Member]
Revenue from External Customer [Line Items]
Revenues									105,078	113,180	158,365
Nuclear Energy [Member] | Nuclear Equipment Operations [Member]
Revenue from External Customer [Line Items]
Revenues									41,354	83,449	134,011
Nuclear Energy [Member] | Nuclear Projects [Member]
Revenue from External Customer [Line Items]
Revenues									8,289	87,002	33,319
mPower [Member]
Revenue from External Customer [Line Items]
Revenues									$278	$1,523	$326

Segment_Reporting_Schedule_of_3

Segment Reporting - Schedule of Revenues by Geographical Area (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries	$837,094	$737,902	$686,006	$662,017	$802,815	$774,834	$886,136	$805,423	$2,923,019	$3,269,208	$3,291,359
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									2,308,987	2,589,521	2,615,387
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									193,786	313,881	288,246
Denmark [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									65,436	56,336	18,504
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									61,972	20,927	6,653
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									59,841	58,775	45,830
Sweden [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									29,786	37,823	101,688
Dominican Republic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									27,399	473	687
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									22,792	22,869	34,364
Chile [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									15,686	9,240	11,582
Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									14,149	9,033	14,461
THAILAND
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									8,113	2,650	3,041
COLOMBIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									8,037	44,622	1,163
Saudi Arabia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									8,003	8,200	7,973
SINGAPORE
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									7,527	2,507	171
France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									7,057	3,930	2,384
Indonesia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									5,324	6,227	7,828
India [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									5,070	4,670	13,306
Finland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									4,926
Vietnam [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									3,829	1,946	459
Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									3,540	4,156	8,477
POLAND
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									3,343	1,748	415
Norway [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									3,199	2,594	9,939
Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									3,156	2,751	2,585
SOUTH AFRICA
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									3,137	2,208	2,993
Argentina [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									3,100	5,737	23,529
TRINIDAD AND TOBAGO
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									2,546	3,264	2,401
Austria [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									2,540	1,854	1,251
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									2,344	3,461	3,384
ISRAEL
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									2,088	2,919	2,502
VENEZUELA
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									2,041	448	832
Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Countries									$34,265	$44,438	$59,324

Segment_Reporting_Schedule_of_4

Segment Reporting - Schedule of Property, Plant and Equipment, Net by Geographical Area (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	$436,635	$447,079	$447,021
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	366,288	367,672	363,447
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	27,480	38,738	45,402
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	12,356	10,980	7,926
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	12,106	8,312	8,302
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	8,638	9,414	9,714
Denmark [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	6,963	8,715	8,565
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	1,536	2,060	2,284
Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Property, Plant and Equipment	$1,268	$1,188	$1,381

Segment_Reporting_Additional_I

Segment Reporting - Additional Information (Detail) (Government Contracts Concentration Risk [Member], Sales Revenue, Net [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Government Contracts Concentration Risk [Member] | Sales Revenue, Net [Member]
Segment Reporting Information [Line Items]
Percentage of revenue from U.S. Government	45.00%	38.00%	34.00%

Quarterly_Financial_Data_Selec

Quarterly Financial Data - Selected Quarterly Financial Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Revenues	$837,094	$737,902	$686,006	$662,017	$802,815	$774,834	$886,136	$805,423	$2,923,019	$3,269,208	$3,291,359
Operating income	-156,540	65,160	35,118	53,640	295,322	82,121	98,706	60,213	-2,622	536,362	346,589
Equity in Income of Investees	5,996	7,308	13,183	15,269	16,345	18,151	18,775	14,787	41,756	68,058	66,709
Net income attributable to The Babcock & Wilcox Company	($103,307)	$61,214	$26,437	$45,044	$165,588	$60,446	$72,870	$47,174	$29,388	$346,078	$227,695
Net income attributable to The Babcock & Wilcox Company, Basic earnings per common share	($0.97)	$0.57	$0.24	$0.41	$1.50	$0.54	$0.65	$0.41	$0.27	$3.09	$1.92
Net income attributable to The Babcock & Wilcox Company, Diluted earnings per common share	($0.97)	$0.57	$0.24	$0.41	$1.48	$0.54	$0.65	$0.41	$0.27	$3.07	$1.91

Quarterly_Financial_Data_Addit

Quarterly Financial Data - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended			3 Months Ended
	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Dec. 31, 2013	Mar. 31, 2014	Dec. 31, 2014
Quarterly Financial Data [Line Items]
Project costs	$30,200,000
Related Tax Benefit (Income Tax)		-15,991,000	184,583,000	101,861,000
Pre-tax defined benefit plan actuarial (gain) loss		241,627,000	-222,925,000	32,040,000
USEC, Inc. Investment [Member]
Quarterly Financial Data [Line Items]
Gain in other income					18,600,000
Related Tax Benefit (Income Tax)	0				0
Impairment of Investment in USEC, Inc						19,100,000
Berlin Station Project [Member]
Quarterly Financial Data [Line Items]
Project costs							7,600,000
Pension and Post Retirement Benefit Plans [Member]
Quarterly Financial Data [Line Items]
Pre-tax defined benefit plan actuarial (gain) loss					-11,100,000	222,900,000		-230,500,000
Adjustment on pension gains						23,000,000
Adjustment on pension gains, net of tax						$17,000,000

Earnings_Per_Share_Computation

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share, Basic and Diluted [Abstract]
Net income attributable to The Babcock & Wilcox Company	($103,307)	$61,214	$26,437	$45,044	$165,588	$60,446	$72,870	$47,174	$29,388	$346,078	$227,695
Weighted average common shares (basic)									108,477,262	111,901,750	118,418,930
Net income attributable to The Babcock & Wilcox Company, Basic earnings per common share	($0.97)	$0.57	$0.24	$0.41	$1.50	$0.54	$0.65	$0.41	$0.27	$3.09	$1.92
Stock options, restricted stock and performance shares									283,830	783,667	602,394
Adjusted weighted average common shares									108,761,092	112,685,417	119,021,324
Net income attributable to The Babcock & Wilcox Company, Diluted earnings per common share	($0.97)	$0.57	$0.24	$0.41	$1.48	$0.54	$0.65	$0.41	$0.27	$3.07	$1.91

Earnings_Per_Share_Computation1

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share, Basic and Diluted [Abstract]
Antidilutive shares related to stock options excluded from the diluted share	1,698,106	442,226	1,082,904