Allison Transmission (ALSN) 10-K 20 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 05, 2015	Jun. 30, 2014
Document Information [Line Items]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	ALSN
Entity Registrant Name	ALLISON TRANSMISSION HOLDINGS INC
Entity Central Index Key	1411207
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		180,053,650
Entity Public Float			$5,148,600,000

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current Assets
Cash and cash equivalents	$263	$184.70
Accounts receivable - net of allowance for doubtful accounts of $0.3 and $0.4, respectively	207.4	175.1
Inventories	143.5	160.4
Deferred income taxes, net	119.7	58.1
Other current assets	24.4	28.6
Total Current Assets	758	606.9
Property, plant and equipment, net	514.6	563.4
Intangible assets, net	1,512	1,610.80
Goodwill	1,941	1,941
Deferred income taxes, net	1.3	1.1
Other non-current assets	77.3	89.4
TOTAL ASSETS	4,804.20	4,812.60
Current Liabilities
Accounts payable	151.7	150.4
Product warranty liability	24	37.4
Current portion of long-term debt	17.9	17.9
Deferred revenue	20.6	29.2
Other current liabilities	131.7	152.3
Total Current Liabilities	345.9	387.2
Product warranty liability	59.6	53.1
Deferred revenue	48.7	43.2
Long-term debt	2,502.60	2,660.40
Deferred income taxes	238.2	76.2
Other non-current liabilities	211.4	153.7
TOTAL LIABILITIES	3,406.40	3,373.80
Commitments and contingencies (see NOTE 17)
STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value, 100,000,000 shares authorized, none issued and outstanding
Paid in capital	1,651	1,631.80
Accumulated deficit	-215.5	-173.8
Accumulated other comprehensive loss, net of tax	-39.5	-21
TOTAL STOCKHOLDERS' EQUITY	1,397.80	1,438.80
TOTAL LIABILITIES & STOCKHOLDERS' EQUITY	4,804.20	4,812.60
Common Stock
STOCKHOLDERS' EQUITY
Common stock	1.8	1.8
Non-voting Common Stock
STOCKHOLDERS' EQUITY
Common stock		$0

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Allowance for doubtful accounts receivables	$0.30	$0.40
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Stock
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	1,880,000,000	1,880,000,000
Common stock, shares issued	179,488,247	183,375,436
Common stock, shares outstanding	179,488,247	183,375,436
Non-voting Common Stock
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	0	1,185
Common stock, shares outstanding	0	1,185

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net sales	$2,127.40	$1,926.80	$2,141.80
Cost of sales	1,151.50	1,084.90	1,187.50
Gross profit	975.9	841.9	954.3
Selling, general and administrative expenses	344.6	334.9	419
Engineering - research and development	103.8	97.1	115.1
Loss associated with impairment of long-lived assets	15.4
Operating income	512.1	409.9	420.2
Interest income	0.9	0.8	0.9
Interest expense	-139.3	-133.7	-152.1
Other expense, net	-5.6	-10.9	-52.8
Income before income taxes	368.1	266.1	216.2
Income tax (expense) benefit	-139.5	-100.7	298
Net income	228.6	165.4	514.2
Basic earnings per share attributable to common stockholders	$1.27	$0.90	$2.83
Diluted earnings per share attributable to common stockholders	$1.25	$0.88	$2.76
Dividends declared per common share	$0.51	$0.42	$0.18
Other comprehensive (loss) income, net of tax:
Foreign currency translation	-7.4	-5	-0.7
Pension and OPEB liability adjustment	-9.1	29	15.1
Available-for-sale securities	-2	-1.1	-1.3
Total other comprehensive (loss) income, net of tax	-18.5	22.9	13.1
Comprehensive income	$210.10	$188.30	$527.30

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$228.60	$165.40	$514.20
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets	98.8	105.3	150
Depreciation of property, plant and equipment	93.8	98.7	102.5
Deferred income taxes	131.8	98	-303.8
Excess tax benefit from stock-based compensation	-24.6	-13.7	-5.3
Loss associated with impairment of long-lived assets	15.4
Stock-based compensation	14.7	13.7	6.4
Amortization of deferred financing costs	8.1	10.9	14.5
Unrealized gain on derivatives	-4.7	-32.8	-26.2
Impairment loss on investments in technology-related initiatives	2	5	14.4
Loss on repayments and repurchases of long-term debt	0.5	0.8	22.1
Other	5.2	2.1	2.1
Changes in assets and liabilities:
Accounts receivable	-35.8	-9.9	29.9
Inventories	12.7	-4.4	-1.8
Accounts payable	2.1	17.6	-29.4
Other assets and liabilities	8.3	-3.2	7.9
Net cash provided by operating activities	556.9	453.5	497.5
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions of long-lived assets	-64.1	-74.4	-123.9
Investments in technology-related initiatives	-5.8	-8.8	-14.4
Collateral for interest rate derivatives	1.7	1.2	-1
Proceeds from disposal of assets	0.3	0.5	0.6
Net cash used for investing activities	-67.9	-81.5	-138.7
CASH FLOWS FROM FINANCING ACTIVITIES:
Repurchase of common stock	-249.8	-99.5
Payments on long-term debt	-157.6	-142.4	-245.4
Dividend payments	-91.6	-77.1	-32.8
Proceeds from exercise of stock options	59.6	46.3	29
Excess tax benefit from stock-based compensation	24.6	13.7	5.3
Taxes paid related to net share settlement of equity awards	-8.4	-3.6
Debt financing costs	-0.9	-14.9	-20.2
Repurchases of long-term debt			-326.9
Payments on notes payable			-2.5
Net cash used for financing activities	-424.1	-277.5	-593.5
Effect of exchange rate changes on cash	13.4	10	0.9
Net increase (decrease) during period	78.3	104.5	-233.8
Cash and cash equivalents at beginning of period	184.7	80.2	314
Cash and cash equivalents at end of period	263	184.7	80.2
Supplemental disclosures:
Interest paid	140	159.2	167.3
Income taxes paid	$5	$3.80	$10.70

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock	Non-voting Common Stock	Treasury Stock	Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss), net of tax
In Millions
Stockholders Equity, Beginning Balance at Dec. 31, 2011	$821.70	$1.80	$0	($0.20)	$1,560.80	($683.70)	($57)
Stock-based compensation	6.4				6.4
Pension and OPEB liability adjustment	15.1						15.1
Foreign currency translation adjustment	-0.7						-0.7
Available-for-sale securities	-1.3						-1.3
Issuance of common stock	29	0			29
Dividends on common stock	-32.8					-32.8
Excess tax benefit from stock-based compensation	5.3				5.3
Net income	514.2					514.2
Stockholders Equity, Ending Balance at Dec. 31, 2012	1,356.90	1.8	0	-0.2	1,601.50	-202.3	-43.9
Stock-based compensation	13.7				13.7
Pension and OPEB liability adjustment	29						29
Foreign currency translation adjustment	-5						-5
Available-for-sale securities	-1.1						-1.1
Issuance of common stock	42.6	0			42.6
Repurchase of common stock	-99.5	0			-39.7	-59.8
Retirement of treasury stock	0.2			0.2
Dividends on common stock	-77.1					-77.1
Excess tax benefit from stock-based compensation	13.7				13.7
Net income	165.4					165.4
Stockholders Equity, Ending Balance at Dec. 31, 2013	1,438.80	1.8	0		1,631.80	-173.8	-21
Stock-based compensation	14.7				14.7
Pension and OPEB liability adjustment	-9.1						-9.1
Foreign currency translation adjustment	-7.4						-7.4
Available-for-sale securities	-2						-2
Issuance of common stock	51	0			51
Repurchase of common stock	-249.8	0	0		-71.1	-178.7
Dividends on common stock	-91.6					-91.6
Excess tax benefit from stock-based compensation	24.6				24.6
Net income	228.6					228.6
Stockholders Equity, Ending Balance at Dec. 31, 2014	$1,397.80	$1.80			$1,651	($215.50)	($39.50)

OVERVIEW

OVERVIEW	12 Months Ended
	Dec. 31, 2014
OVERVIEW	NOTE 1.	OVERVIEW
	Overview
	Allison Transmission Holdings, Inc. and its subsidiaries (“Allison,” the “Company” or “we”) design and manufacture commercial and defense fully-automatic transmissions. The business was founded in 1915 and has been headquartered in Indianapolis, Indiana since inception. Allison was an operating unit of General Motors Corporation (“Old GM”) from 1929 until 2007, when Allison once again became a stand-alone company. In March 2012, Allison began trading on the New York Stock Exchange under the symbol, “ALSN”.
	We have approximately 2,700 employees and 13 different transmission product lines. Although approximately 80% percent of revenues were generated in North America in 2014, we have a global presence by serving customers in Europe, Asia, South America and Africa. We serve customers through an independent network of approximately 1,400 independent distributor and dealer locations worldwide.

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2014
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	NOTE 2.	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Basis of Presentation and Principles of Consolidation
	The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The information herein reflects all normal recurring material adjustments, which are, in the opinion of management, necessary for the fair statements of the results for the periods presented. The consolidated financial statements herein consist of all wholly-owned domestic and foreign subsidiaries with all significant intercompany transactions eliminated.
	These consolidated financial statements present the financial position, results of comprehensive income, cash flows and statements of equity. Certain immaterial reclassifications have been made in the consolidated financial statements of prior periods to conform to the current period presentation. These reclassifications have no impact on previously reported net income, total stockholders’ equity or cash flows.
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities and the reported amounts of revenue and expenses. Significant estimates include, but are not limited to, allowance for doubtful accounts, sales allowances, government price adjustments, fair market values and future cash flows associated with goodwill, indefinite-life intangibles, long-lived asset impairment tests, useful lives for depreciation and amortization, warranty liability, determination of discount and other assumptions for pension and other postretirement benefit expense, income taxes and deferred tax valuation allowances, derivative valuation, and contingencies. The Company’s accounting policies involve the application of judgments and assumptions made by management that include inherent risks and uncertainties. Actual results could differ materially from these estimates. Changes in estimates are recorded in results of operations in the period that the events or circumstances giving rise to such changes occur.
	Segment Reporting
	In accordance with the Financial Accounting Standards Board (“FASB”) authoritative accounting guidance on segment reporting, the Company has one operating segment and reportable segment. The Company is in one line of business, which is the manufacture and distribution of fully-automatic transmissions.
	Government Grants
	The Company recognizes government grants when there is reasonable assurance that the Company will comply with the conditions attached to the grant arrangement and the funds will be received. When the government grants relate to reimbursement of costs, the grant income is recognized in Other expense, net in the Consolidated Statements of Comprehensive Income. When the government grants relate to a reimbursement of capital expenditures, the grants are recognized as a reduction of the basis of the assets in the Consolidated Balance Sheets.
	Cash and Cash Equivalents
	Cash equivalents are defined as short-term, highly-liquid investments with original maturities of 90 days or less. Under the Company’s cash management system, checks issued but not presented to banks may result in book overdraft balances for accounting purposes and are classified within Accounts payable in the Consolidated Balance Sheets. The change in book overdrafts is reported as a component of operating cash flows for Accounts payable.
	Marketable Securities
	The Company determines the appropriate classification of all marketable securities as “held-to-maturity,” “available-for-sale” or “trading” at the time of purchase, and re-evaluates such classifications as of each balance sheet date. As of December 31, 2014, the Company’s marketable securities are classified as either available-for-sale or trading.
	Available-for-sale securities are carried at fair value with the unrealized gain or loss reported in Accumulated other comprehensive loss (“AOCL”). Unrealized gains or losses considered to be “other-than-temporary” are recognized in income. Trading securities are carried at fair value with the unrealized gain or loss recognized in Other expense, net. The fair value of the Company’s investment securities is determined by currently available market prices. See NOTE 6 for more details.
	Allowance for Doubtful Accounts
	The allowance for doubtful trade accounts receivable reflects estimated losses to be incurred in the collection of the receivables. Estimated losses are based on historical collection experience as well as a review by management of the current status of all receivables. Account balances are charged against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote.
	Inventories
	Inventories are stated at the lower of cost or market. The Company determines cost using the first-in, first-out method. The Company analyzes inventory on a quarterly basis to determine whether it is excess or obsolete inventory. Any decline in carrying value of estimated excess or obsolete inventory is recorded as a reduction of inventory and as an expense included in Cost of sales in the period it is identified.
	Property, Plant and Equipment
	Property, plant and equipment are recorded at cost less accumulated depreciation. Depreciation expense is recorded using the straight-line method over the following estimated lives:
			Range in Years
	Land improvements		5 – 30
	Buildings and building improvements		10 – 40
	Machinery and equipment		2 – 20
	Software		2 – 5
	Special tools		2 – 10
	Software represents the costs of software developed or obtained for internal use. Software costs are amortized on a straight-line basis over their estimated useful lives. Software assets are reviewed for impairment when events or circumstances indicate that the carrying value may not be recoverable over the remaining lives of the assets. Upgrades and enhancements are capitalized if they result in added functionality, which enables the software to perform tasks it was previously incapable of performing. Software maintenance, training, data conversion and business process reengineering costs are expensed in the period in which they are incurred.
	Special tooling represents the costs to design and develop tools, dies, jigs and other items owned by the Company and used in the manufacture of components by suppliers under long-term supply agreements. Special tooling is depreciated over the tool’s expected life. Special tooling used in the development of new technology is expensed as incurred. Engineering, testing and other costs incurred in the design and development of production parts are expensed as incurred.
	Impairment of Long-Lived Assets
	The carrying value of long-lived assets is evaluated whenever events or circumstances indicate that the carrying value of an asset may not be recoverable. Events or circumstances that would result in an impairment review primarily include a significant change in the use of an asset, or the planned sale or disposal of an asset. The asset would be considered impaired when there is no future use planned for the asset or the future net undiscounted cash flows generated by the asset or asset group are less than its carrying value. An impairment loss would be recognized based on the amount by which the carrying value exceeds fair value.
	Assumptions and estimates used to determine cash flows in the evaluation of impairment and the fair values used to determine the impairment are subject to a degree of judgment and complexity. Any changes to the assumptions and estimates resulting from changes in actual results or market conditions from those anticipated may affect the carrying value of long-lived assets and could result in an impairment charge.
	As a result of events and circumstances in the fourth quarter of 2014, the Company reviewed certain of its long-lived assets related to the production of the H3000 and H4000 hybrid-propulsion systems, resulting in a $15.4 million loss recorded for the year ended December 31, 2014. The loss, determined by using future net discounted cash flows, included approximately $1.7 million of accrued expenses related to the impairment of the long-lived assets. Deteriorating market conditions for hybrid-propulsion vehicles, principally as a result of decreased fuel costs, alternative fuels and other technologies, significantly contributed to the future cash flows of the related assets being less than the carrying value of those assets.
	Goodwill and Other Intangible Assets
	Goodwill represents the excess of purchase price paid over the fair value of net assets acquired. In accordance with the FASB’s authoritative accounting guidance on goodwill, the Company does not amortize goodwill but rather evaluates it for impairment on an annual basis, or more often if events or circumstances change that could cause goodwill to become impaired. Goodwill is tested for impairment at the reporting unit level, which is the same as the Company’s one operating and reportable segment. The Company has elected to perform its annual impairment test on October 31 of every year. A multi-step impairment test is performed on goodwill. In Step 0, the Company has the option to evaluate various qualitative factors to determine the likelihood of impairment. If determined that the fair value is more likely than not less than the carrying value, then the Company is required to perform Step 1. If the Company does not elect to perform Step 0, it can voluntarily proceed directly to Step 1. In Step 1, the Company performs a quantitative analysis to compare the fair value of its reporting unit to its carrying value including goodwill. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not considered impaired, and the Company is not required to perform further testing. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then the Company must perform Step 2 of the impairment test in order to determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, then the Company would record an impairment loss equal to the difference.
	Goodwill impairment testing for 2014 was performed by assessing certain qualitative trends and factors. The Company’s qualitative assessment included an assessment of business changes, economic outlook, financial trends and forecasts, growth rates, credit ratings, equity ratings, discount rates, industry data and other relevant qualitative factors. Events or circumstances that could unfavorably impact the key assumptions include lower net sales driven by market conditions, our inability to execute on marketing programs and/or delay in the introduction of new products, lower gross margins as a result of market conditions or failure to obtain forecasted cost reductions, or a higher discount rate as a result of market conditions. While unpredictable and inherently uncertain, the Company believes its forecast estimates are reasonable and incorporate assumptions that similar market participants would use in their estimates of fair value. These trends and factors were compared to, and based on, the assumptions used in the quantitative assessment performed in 2013. After reviewing various qualitative factors, the Company’s 2014 annual goodwill impairment test indicated that the fair value of the reporting unit more likely than not exceeded its carrying value, indicating no impairment.
	Other intangible assets have both indefinite and finite useful lives. Intangible assets with indefinite useful lives, such as the Company’s trade name, are not amortized but are tested annually for impairment. The Company has elected to perform our annual trade name impairment test on October 31 of every year and follow a similar multi-step impairment test that is performed on goodwill. After reviewing various qualitative factors, the Company’s 2014 annual trade name impairment test indicated that the fair value of the trade name more likely than not exceeded its carrying value, indicating no impairment. The qualitative review included an assessment of various key assumptions and factors including, among others, an assessment of business changes, economic outlooks, financial trends and forecasts, royalty savings rates, credit ratings, equity ratings and discount rates. Events or circumstances that could unfavorably impact the key assumptions include lower net sales driven by market conditions, our inability to execute on marketing programs and/or delay in introduction of new products, and higher discount rate as a result of market conditions. While unpredictable and inherently uncertain, we believe the forecast estimates are reasonable and incorporate those assumptions that similar market participants would use in their estimates of fair value. These trends and factors were compared to, and based on, the assumptions used in the quantitative assessment performed in 2013. After reviewing various qualitative factors, the fair value of trade name exceeded the respective carrying value.
	Intangible assets with finite lives are amortized over their estimated useful lives and reviewed for impairment when circumstances change that would create a triggering event. Customer relationships are amortized over the life in which expected benefits are to be consumed. The other remaining finite useful life intangibles are amortized on a straight-line basis over their useful lives. The Company evaluates the remaining useful life of the other intangible assets on a periodic basis to determine whether events or circumstances warrant a revision to the remaining useful life. Assumptions and estimates about future values and remaining useful lives of the Company’s intangible and other long-lived assets are complex and subjective. They can be affected by a variety of factors, including external factors such as industry and economic trends, and internal factors, such as changes in the Company’s business strategy and internal forecasts. Although management believes the historical assumptions and estimates are reasonable and appropriate, different assumptions and estimates could materially impact the Company’s reported financial results.
	NOTE 5 provides further information on Goodwill and Other intangible assets.
	Deferred Financing Costs
	Deferred financing costs are stated at cost as a component of other non-current assets and amortized over the life of the related debt using the effective interest method. Amortization of deferred financing costs is recorded as part of interest expense and totaled $8.1 million, $10.9 million and $14.5 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Financial Instruments
	The Company’s cash equivalents are invested in U.S. Government backed securities and recorded at fair value in the Consolidated Balance Sheets. The carrying values of accounts receivable and accounts payable approximate fair value due to their short-term nature. The Company’s financial derivative instruments, including interest rate swaps and foreign currency and commodity forward contracts are carried at fair value on the Consolidated Balance Sheets. Refer to NOTE 6 for more detail. The Company’s long-term debt obligations are carried at historical amounts with the Company providing fair value disclosure in NOTE 7.
	Insurable Liabilities
	The Company records liabilities for its medical, workers’ compensation, long-term disability, product, general and auto liabilities. The determination of these liabilities and related expenses is dependent on claims experience. For most of these liabilities, claims incurred but not yet reported are estimated based upon historical claims experience.
	Revenue Recognition
	The Company records sales when title has transferred to the customer, there is evidence of an agreement, the sales price is fixed or determinable, delivery has occurred or services have been rendered, and collectability is reasonably assured. The Company sells Extended Transmission Coverage (“ETC”) for which sales are deferred. ETC sales are recognized ratably over the period of the ETC, which typically ranges from two to five years after initial sale. Costs associated with ETC programs are recorded as incurred during the extended period. Distributor and customer sales incentives, consisting of allowances and other rebates, are estimated at the time of sale based upon the Company’s history and experience and are recorded as a reduction to Net sales. Incentive programs are generally product specific or region specific. Some factors used in estimating the cost of incentives include the number of transmissions that will be affected by the incentive program and rate of acceptance of any incentive program. If the actual number of affected transmissions differs from this estimate, or if a different mix of incentives is actually paid, the impact on Net sales would be recorded in the period that the change was identified. Consideration given to commercial customers recorded as a reduction of Net sales in the Consolidated Statements of Comprehensive Income included $66.9 million, $65.2 million, and $59.9 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Sales under U.S. government production contracts are recorded when the product is accepted, title has transferred to the U.S. government, the sales price is fixed or determinable, and delivery has occurred. Deferred revenue arises from cash received in advance of the culmination of the earnings process and is recognized as revenue in future periods when the applicable revenue recognition criteria have been met. Under the terms of the U.S. government contracts, there are certain price reduction clauses and provisions for potential price reductions which are estimated at the time of sale based upon the Company’s history and experience and are recorded as a reduction to Net sales. Potential reductions may be attributed to a change in projected sales volumes or plant efficiencies which impact overall costs. As of December 31, 2014 and 2013, the Company had $63.1 million and $49.6 million recorded in the price reduction reserve account, respectively.
	Due to requests from the U.S. government, the Company billed, but did not ship certain tracked transmissions during 2013. Based on the lack of a fixed delivery date from the U.S. government, the Company deferred approximately $8.8 million of net sales for these transmissions until they were shipped in 2014. See NOTE 10 for additional details.
	The Company classifies shipping and handling billed to customers in Net sales and shipping and handling costs in Cost of sales, in accordance with authoritative accounting guidance.
	The Company contracts with various third parties to provide engineering services. These services are recorded as Net sales in accordance with the terms of the contract. The saleable engineering recorded was $7.4 million, 12.4 million and $7.8 million for the years ended December 31, 2014, 2013 and 2012, respectively. The associated costs are recorded in Cost of sales.
	Warranty
	Provisions for estimated expenses related to product warranties are made at the time products are sold. Warranty claims arise when a transmission fails while in service during the relevant warranty period. The warranty reserve is adjusted in Selling, general and administrative expenses based on the Company’s current and historical warranty claims paid and associated repair costs. These estimates are established using historical information including the nature, frequency, and average cost of warranty claims and are adjusted as actual information becomes available. From time to time, the Company may initiate a specific field action program. As a result of the uncertainty surrounding the nature and frequency of specific field action programs, the liability for such programs is recorded when the Company commits to an action. The Company reviews and assesses the liability for these programs on a quarterly basis. The Company also assesses its ability to recover certain costs from its suppliers and records a receivable from the supplier when it believes a recovery is probable.
	Research and Development
	The Company incurs costs in connection with research and development programs that are expected to contribute to future earnings. Such costs are charged to Engineering — research and development as incurred.
	Foreign Currency Translation
	Most of the subsidiaries outside the United States prepare financial statements in currencies other than the U.S. dollar. The functional currency for all these subsidiaries is the local currency, except for the Company’s Hong Kong and Middle East subsidiaries which currently use the U.S. dollar as their functional currency. Balances are translated at period-end exchange rates for assets and liabilities and monthly weighted-average exchange rates for revenues and expenses. The translation gains (losses) are stated as a component of AOCL as disclosed in NOTE 16.
	Derivative Instruments
	In the normal course of business, the Company is exposed to fluctuations in interest rates, foreign currency exchange rates, and commodity prices. The risk is managed through the use of financial derivative instruments including interest rate swaps and commodity and foreign currency forward contracts. Despite the fact that the Company either has not elected or does not qualify for hedge accounting treatment on all of its derivative instruments, the contracts are used strictly as an economic hedge and not for speculative purposes. As necessary, the Company adjusts the values of the derivative instruments for counter-party or credit risk. NOTE 8 provides further information on the accounting treatment of the Company’s derivative instruments.
	Income Taxes
	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the expected future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The future tax benefits associated with operating loss and tax credit carryforwards are recognized as deferred tax assets. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled.
	The need to establish a valuation allowance against the deferred tax assets is assessed periodically based on a more-likely-than-not realization threshold, in accordance with the FASB’s authoritative accounting guidance on income taxes. Appropriate consideration is given to all positive and negative evidence related to that realization. This assessment considers, among other matters, the nature, frequency and severity of recent losses, forecasts of future profitability, the duration of statutory carryforward periods, and experience with tax attributes expiring unused and tax planning alternatives. The weight given to these considerations depends upon the degree to which they can be objectively verified.
	Stock-Based Compensation
	The Company maintains a stock-based compensation plan which allows employees (including executive officers), consultants and directors to receive equity awards. The Company has adopted the FASB’s authoritative accounting guidance on share-based payments and recognizes the fair value of the awards as compensation expense over the vesting period. The accounting guidance also requires that forfeitures be estimated over the vesting period of an award instead of being recognized as a reduction of compensation expense when the forfeiture actually occurs.
Pension and Post-retirement Benefit Plans
For pension and other post-retirement benefits (“OPEB”) plans in which employees participate, costs are determined within the FASB’s authoritative accounting guidance set forth in employers’ defined benefit pensions including accounting for settlements and curtailments of defined benefit pension plans, termination of benefits and accounting for post-retirement benefits other than pensions. In accordance with the authoritative accounting guidance, the Company recognizes the funded status of its defined benefit pension plans and OPEB plan in its Consolidated Balance Sheets with a corresponding adjustment to AOCL, net of tax.
Post-retirement benefit costs consist of service cost, interest cost on accrued obligations and the expected return on assets (calculated using a smoothed market value of assets). Any difference between actual and expected returns on assets during a year and actuarial gains and losses on liabilities together with any prior service costs are charged (or credited) to income over the average remaining service lives of employees.
The benefit cost components shown in the Consolidated Statements of Comprehensive Income are based upon various actuarial assumptions and methodologies as prescribed by authoritative accounting guidance. These assumptions include discount rates, expected return on plan assets, health care cost trend rates, inflation, rate of compensation increases, population demographics, mortality rates and other factors. The Company reviews all actuarial assumptions on an annual basis. Changes in key economic indicators can change these assumptions. These assumptions, along with the actual value of assets at the measurement date, will impact the calculation of pension expenses for the year. For instance, the effect of a one percentage point decrease in the assumed discount rate would result in an increase in the December 31, 2014 defined benefit pension plans obligation of approximately $20.0 million. Similarly, a one percentage point decrease in the assumed discount rate would result in an increase in the December 31, 2014 OPEB obligation of approximately $23.7 million.
Recently Issued Accounting Pronouncements
In August 2014, the FASB issued authoritative accounting guidance on the disclosure of uncertainties about an entity’s ability to continue as a going concern. The guidance requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that financial statements are available to be issued when applicable) and to provide related footnote disclosures. The guidance is effective prospectively for fiscal years beginning after December 15, 2016, but can be early-adopted. While the adoption of this guidance is not expected to have an effect on the Company’s consolidated financial statements, it could affect the disclosure applied under these circumstances in the future.
In May 2014, the FASB issued authoritative accounting guidance on a company’s accounting for revenue from contracts with customers. The guidance applies to all companies that enter into contracts with customers to transfer goods, service or nonfinancial assets. The guidance requires these companies to 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 or services. The guidance also requires improved disclosures regarding the nature, timing, amount and uncertainty of revenue that is recognized. The guidance is effective prospectively for fiscal years beginning after December 15, 2016. Management is currently assessing the potential impact of the adoption of this guidance on the Company’s consolidated financial statements.

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2014
INVENTORIES	NOTE 3.	INVENTORIES
	Inventories consisted of the following components (dollars in millions):
			December 31,		December 31,
			2014		2013
	Purchased parts and raw materials		$	72.3	$	79.7
	Work in progress			6.1		5.7
	Service parts			46.5		45.8
	Finished goods			18.6		29.2
	Total inventories		$	143.5	$	160.4
	Inventory components shipped to third parties, primarily cores, parts to re-manufacturers, and parts to contract manufacturers, in which the Company has an obligation to buy back, are included in purchased parts and raw materials, with an offsetting liability in Other current liabilities. See NOTE 12, “Other Current Liabilities” for more information.

PROPERTY_PLANT_AND_EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	12 Months Ended
	Dec. 31, 2014
PROPERTY, PLANT AND EQUIPMENT	NOTE 4.	PROPERTY, PLANT AND EQUIPMENT
	The cost and accumulated depreciation of property, plant and equipment are as follows (dollars in millions):
			December 31,			December 31,
			2014			2013
	Land and land improvements		$	23.6		$	20.3
	Buildings and building improvements			281.6			271.4
	Machinery and equipment			576.2			567.7
	Software			117			112.9
	Special tools			143.6			143.4
	Construction in progress			39.9			48.6
	Total property, plant and equipment			1.181.9			1,164.30
	Accumulated depreciation			(667.3	)		(600.9	)
	Property, plant and equipment, net		$	514.6		$	563.4
	Depreciation of property, plant and equipment was $93.8 million, $98.7 million and $102.5 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	During 2014, the Company recorded an impairment of certain machinery and equipment, and special tools associated with the production of the H3000 and H4000 hybrid-propulsion systems. See NOTE 2, “Impairment of long-lived assets” for more information.

GOODWILL_AND_OTHER_INTANGIBLE_

GOODWILL AND OTHER INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2014
GOODWILL AND OTHER INTANGIBLE ASSETS	NOTE 5.	GOODWILL AND OTHER INTANGIBLE ASSETS
	As of December 31, 2014 and 2013, the carrying amount of the Company’s Goodwill was $1,941.0 million.
	The following presents a summary of other intangible assets (dollars in millions):
			December 31, 2014							December 31, 2013
			Intangible		Accumulated			Intangible		Intangible		Accumulated			Intangible
			assets, gross		amortization			assets, net		assets, gross		amortization			assets, net
	Other intangible assets:
	Trade name		$	870	$	—		$	870	$	870	$	—		$	870
	Customer relationships - defense			62.3		(27.9	)		34.4		62.3		(24.4	)		37.9
	Customer relationships - commercial			831.8		(426.9	)		404.9		831.8		(374.9	)		456.9
	Proprietary technology			476.3		(282.0	)		194.3		476.3		(243.9	)		232.4
	Non-compete agreement			17.3		(12.8	)		4.5		17.3		(11.1	)		6.2
	Patented technology - defense			28.2		(24.5	)		3.7		28.2		(21.2	)		7
	Tooling rights			4.5		(4.3	)		0.2		4.5		(4.1	)		0.4
	Patented technology - commercial			260.6		(260.6	)		—		260.6		(260.6	)		—
	Total		$	2,551.00	$	(1,039.0	)	$	1,512.00	$	2,551.00	$	(940.2	)	$	1,610.80
	Amortization of intangible assets was $98.8 million, $105.3 million and $150.0 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	As of December 31, 2014, the net carrying value of the Company’s Goodwill and Other intangible assets, net was $3,453.0 million.
	Amortization expense related to other intangible assets for the next five years and thereafter is expected to be (dollars in millions):
			2015		2016			2017		2018		2019			Thereafter
	Amortization expense		$	97.1	$	92.4		$	89.7	$	87.2	$	85.7		$	189.9

FAIR_VALUE_OF_FINANCIAL_INSTRU

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2014
FAIR VALUE OF FINANCIAL INSTRUMENTS	NOTE 6.	FAIR VALUE OF FINANCIAL INSTRUMENTS
	In accordance with the FASB’s authoritative accounting guidance on fair value measurements, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company utilizes market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated, or generally unobservable. The Company primarily applies the market approach for recurring fair value measurements and utilizes the best available information that maximizes the use of observable inputs and minimizes the use of unobservable inputs. The Company is able to classify fair value balances based on the observability of those inputs. The accounting guidance establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy defined by the relevant guidance are as follows:
	Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 1 primarily consists of financial instruments such as exchange-traded derivatives, listed equities and publicly traded bonds.
	Level 2 — Pricing inputs are other than quoted prices in active markets included in Level 1, which are either directly or indirectly observable as of the reported date. Level 2 includes financial instruments that are valued using quoted prices in markets that are not active and those financial instruments that are valued using models or other valuation methodologies. These models are primarily industry standard models that consider various assumptions, including quoted forward prices for commodities, time value, volatility factors, and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace throughout the full term of the instrument, can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace.
	Level 3 — Pricing inputs include significant inputs that are generally less observable from objective sources. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value. At each balance sheet date, the Company performs an analysis of all instruments subject to authoritative accounting guidance and includes, in Level 3, all of those whose fair value is based on significant unobservable inputs. As of December 31, 2014 and 2013, the Company did not have any Level 3 financial assets or liabilities.
	The Company’s assets and liabilities that are measured at fair value include cash and cash equivalents, available-for-sale securities, derivative instruments, assets held in a rabbi trust and a deferred compensation obligation. The Company’s cash equivalents consist of short-term U.S. government backed securities. The Company’s available-for-sale securities consist of ordinary shares of Torotrak plc (“Torotrak”) associated with a license and exclusivity agreement with Torotrak. Torotrak’s listed shares are traded on the London Stock Exchange under the ticker symbol “TRK.” The Company’s derivative instruments consist of interest rate swaps, foreign currency forward contracts and commodity swaps. The Company’s assets held in the rabbi trust consist principally of publicly available mutual funds and target date retirement funds. The Company’s deferred compensation obligation is directly related to the fair value of assets held in the rabbi trust.
	The Company’s valuation techniques used to calculate the fair value of cash and cash equivalents, available-for-sale securities, assets held in the rabbi trust and the deferred compensation obligation represent a market approach in active markets for identical assets that qualify as Level 1 in the fair value hierarchy. The Company’s valuation techniques used to calculate the fair value of derivative instruments represent a market approach with observable inputs that qualify as Level 2 in the fair value hierarchy.
	The foreign currency contracts consist of forward rate contracts which are intended to hedge exposure of transactions denominated in certain currencies and reduce the impact of currency price volatility on the Company’s financial results. The commodity contracts consist of forward rate contracts which are intended to hedge exposure of transactions involving purchases of component parts and energy to power our facilities, reducing the impact of commodity price volatility on the Company’s financial results.
	For the fair value measurement of foreign currency derivatives, the Company uses forward foreign exchange rates received from the issuing financial institution. These rates are periodically corroborated by comparing to third-party broker quotes. The foreign currency hedges are accounted for within the authoritative accounting guidance set forth on accounting for derivative instruments and hedging activities and have been recorded at fair value based upon quoted market rates. The fair values are included in Other current and non-current assets and liabilities in the Consolidated Balance Sheets. The Company generally does not elect to apply hedge accounting for these foreign currency contracts, and as a result, unrealized fair value adjustments and realized gains and losses are recorded in Other expense, net in the Consolidated Statements of Comprehensive Income during the period of change.
	For the fair value measurement of commodity derivatives, the Company uses forward prices received from the issuing financial institution. These rates are periodically corroborated by comparing to third-party broker quotes. The commodity derivatives are accounted for within the authoritative accounting guidance set forth on accounting for derivative instruments and hedging activities and have been recorded at fair value based upon quoted market rates. The fair values are included in Other current and non-current assets and liabilities in the Consolidated Balance Sheets. The Company has either not qualified for or not elected hedge accounting treatment for these commodity contracts, and as a result, unrealized fair value adjustments and realized gains and losses are recorded in Other expense, net in the Consolidated Statements of Comprehensive Income.
	For the fair value measurement of interest rate derivatives, the Company uses valuations from the issuing financial institution. The Company corroborates the valuation through the use of third-party valuation services using a standard replacement valuation model. The floating-to-fixed interest rate swaps are based on the London Interbank Offered Rate (“LIBOR”) which is observable at commonly quoted intervals. The fair values are included in other current and non-current assets and liabilities in the Consolidated Balance Sheets. The Company has not qualified for hedge accounting treatment for the interest rate swaps and, as a result, fair value adjustments are charged directly to Interest expense in the Consolidated Statements of Comprehensive Income.
	The following table summarizes the fair value of the Company’s financial assets and (liabilities) as of December 31 (dollars in millions):
			Fair Value Measurements Using
			Quoted Prices in Active						Significant Other						TOTAL
			Markets for Identical						Observable Inputs (Level 2)
			Assets (Level 1)
			2014			2013			2014			2013			2014			2013
	Cash equivalents		$	55		$	5		$	—		$	—		$	55		$	5
	Available-for-sale securities			8.6			8.2			—			—			8.6			8.2
	Rabbi trust assets			2.9			1.3			—			—			2.9			1.3
	Deferred compensation obligation			(2.9	)		(1.3	)		—			—			(2.9	)		(1.3	)
	Derivative assets			—			—			0			1.6			0			1.6
	Derivative liabilities			—			—			(15.4	)		(21.4	)		(15.4	)		(21.4	)
	Total		$	63.6		$	13.2		$	(15.4	)	$	(19.8	)	$	48.2		$	(6.6	)

DEBT

DEBT	12 Months Ended
	Dec. 31, 2014
DEBT	NOTE 7.	DEBT
	Long-term debt and maturities are as follows (dollars in millions):
			December 31,		December 31,
			2014		2013
	Long-term debt:
	Senior Secured Credit Facility Term B-2 Loan, variable, due 2017		$	283.6	$	423.5
	Senior Secured Credit Facility Term B-3 Loan, variable, due 2019			1,765.60		1,783.50
	Senior Notes, fixed 7.125%, due 2019			471.3		471.3
	Total long-term debt		$	2,520.50	$	2,678.30
	Less: current maturities of long-term debt			17.9		17.9
	Total long-term debt less current portion		$	2,502.60	$	2,660.40
	Principal payments required on long-term debt during the next five years are as follows:
			Required Principal Payments
	(dollars in millions)		2015		2016		2017		2018		2019
	Payment		$	17.9	$	17.9	$	301.4	$	17.9	$	2,165.40
	As of December 31, 2014, the Company had $283.6 million of indebtedness associated with Allison Transmission, Inc.’s (“ATI”), the Company’s wholly-owned subsidiary, Senior Secured Credit Facility Term B-2 Loan due 2017 (“Term B-2 Loan”) and $1,765.6 million of indebtedness associated with ATI’s Senior Secured Credit Facility Term B-3 Loan due 2019 (“Term B-3 Loan” and together with the Term B-2 Loan and revolving credit facility, the “Senior Secured Credit Facility”). The Company also had indebtedness of $471.3 million of ATI’s 7.125% senior cash pay notes due May 2019 (“7.125% Senior Notes”).
	The fair value of the Company’s long-term debt obligations as of December 31, 2014 was $2,515.9 million. The fair value is based on quoted Level 2 market prices of the Company’s debt as of December 31, 2014. It is not expected that the Company would be able to repurchase a significant amount of its debt at these levels. The difference between the fair value and carrying value of the long-term debt is driven primarily by trends in the financial markets.
	Senior Secured Credit Facility
	In March 2012, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $801.1 million in principal amount of term loan debt from August 2014 to August 2017 and to increase the applicable margin at the Company’s option to either (a) 3.50% over the LIBOR or (b) 2.50% over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.50%. As a result of the debt modification, the Company recorded an additional $2.3 million as deferred financing fees in the Consolidated Balance Sheets and extended the amortization period of $5.1 million of deferred financing fees from 2014 to 2017.
	In August 2012, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $850.0 million of term loan debt from August 2014 to August 2019 and to increase the applicable margin at the Company’s option to either (a) 3.25% or 3.00%, subject to the Company’s total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 2.25% or 2.00%, subject to the Company’s total leverage ratio, over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.5% (which may not be less than 2.00%). The amendment was treated as an extinguishment of debt under GAAP, and thus the Company expensed $4.5 million of deferred financing fees and recorded $16.1 million of new deferred financing fees in the consolidated financial statements.
	In October 2012, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $300.0 million of term loan debt from August 2014 to August 2019 and to increase the applicable margin at the Company’s option to either (a) 3.25% or 3.00%, subject to the Company’s total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 2.25% or 2.00%, subject to the Company’s total leverage ratio, over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.50% (which may not be less than 2.00%). The amendment was treated as an extinguishment of debt under GAAP, and thus the Company expensed $1.4 million of deferred financing fees and recorded $1.8 million of new deferred financing fees in the consolidated financial statements.
	In February 2013, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to refinance $793.1 million of term loan debt and decrease the applicable margin for such term loans at the Company’s option to either (a) 3.00% over the LIBOR or (b) 2.00% over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.50%. In February 2013, ATI also entered into an additional amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $411.4 million of term loan debt from August 2014 to August 2017 and to increase the applicable margin at the Company’s option to either (a) 3.00% over the LIBOR or (b) 2.00% over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.50%. The February 2013 amendments were treated as a modification of debt under GAAP, and the Company expensed $1.0 million of deferred financing fees and recorded $1.6 million of new deferred financing fees in the consolidated financial statements.
	In August 2013, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to refinance $1,139.3 million of term loan debt and decrease the applicable margin for such term loans at the Company’s option to either (a) 2.75% or 2.50%, subject to the Company’s total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 1.75% or 1.50%, subject to the Company’s total leverage ratio, over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.50% (which may not be less than 2.00%). The amendment was treated as a modification of debt under GAAP, and thus the Company expensed $2.1 million of deferred financing fees and recorded $1.0 million of new deferred financing fees in the consolidated financial statements.
	In December 2013, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $650.0 million of term loan debt from August 2017 to August 2019 and to reduce the applicable margin at the Company’s option to either (a) 2.75% or 2.50%, subject to the Company’s total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 1.75% or 1.50%, subject to the Company’s total leverage ratio, over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.50% (which may not be less than 2.00%). The amendment also extended the maturity of the revolving credit facility to January 2019, increased the borrowing capacity to $410.0 million, reduced the interest rate spread to either 2.25%, 2.00% or 1.75% on LIBOR loans or 1.25%, 1.00% or 0.75% on Base Rate loans, subject to the Company’s total leverage ratio, reduced the commitment fee to either 0.375% or 0.25%, subject to the Company’s total leverage ratio, and increased the letters of credit sublimit to $75.0 million. Lastly, the amendment changed the requirement of the maximum total senior secured leverage ratio, so that it is only applicable to the revolving portion of the Senior Secured Credit Facility and is tested only when revolving commitments (including letters of credit) remain outstanding at the end of any fiscal quarter. The amendment to the term loans was treated as a modification of debt under GAAP, and thus the Company expensed $0.5 million of deferred financing fees and recorded $10.1 million of new deferred financing fees in the consolidated financial statements. The amendment to the revolving portion of the Senior Secured Credit Facility was treated as a modification of debt under GAAP, and thus the Company expensed $0.4 million of deferred financing fees and recorded $2.1 million of new deferred financing fees in the consolidated financial statements.
	In April 2014, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to refinance Term B-2 Loan. The interest rate margin applicable to such refinanced loan is at the Company’s option, either (a) 2.75% over the LIBOR or (b) 1.75% over the greater of the prime lending rate provided by the British Banking Association or the federal funds effective rate published by the Federal Reserve Bank of New York plus 0.50%. The Company recorded $0.3 million of new deferred financing fees in the condensed consolidated financial statements. As of December 31, 2014, these rates were approximately 2.92% and 3.75% on the Term B-2 Loan and Term B-3 Loan, respectively, and the weighted average rate on the Senior Secured Credit Facility was approximately 3.64%. The Senior Secured Credit Facility requires minimum quarterly principal payments on the Term B-2 Loan and Term B-3 Loan as well as prepayments from certain net cash proceeds of non-ordinary course asset sales and casualty and condemnation events and from a percentage of excess cash flow, if applicable. Due to voluntary prepayments, the Company has fulfilled all Term B-2 Loan required quarterly payments through its maturity date of 2017. During 2014, the Company made principal payments of $140.0 million on the Term B-2 Loan, resulting in a loss of $0.5 million associated with the write off of related deferred debt issuance costs. The minimum required quarterly principal payment on the Term B-3 Loan is $4.5 million and remains through its maturity date of 2019. As of December 31, 2014, there had been no payments required for certain net cash proceeds of non-ordinary course asset sales and casualty and condemnation events. The remaining principal balance on each loan is due upon maturity.
	The Senior Secured Credit Facility is collateralized by a lien on substantially all assets of the Company including all of ATI’s capital stock and all of the capital stock or other equity interest held by the Company, ATI and each of the Company’s existing and future U.S. subsidiary guarantors (subject to certain limitations for equity interests of foreign subsidiaries and other exceptions set forth in the terms of the Senior Secured Credit Facility).
	In accordance with the Senior Secured Credit Facility, net cash proceeds of non-ordinary course asset sales, casualty and condemnation events will only be required to prepay the term loan if the Company does not reinvest or commit to reinvest such net cash proceeds in assets to be used in its business or to make certain other permitted investments within 15 months of the related transaction or event, subject to certain limitations. The Company must apply 50% of its annual excess cash flow (as defined in the Senior Secured Credit Facility) to the prepayment of the Senior Secured Credit Facility, however this percentage reduces to certain levels and eventually to zero upon achievement of certain total senior secured leverage ratios. For the year ended December 31, 2014 and 2013, the Company was not required to make an excess cash flow payment.
	The Senior Secured Credit Facility also provides for revolving credit borrowings. In 2014, ATI increased the revolving commitments available under the revolving portion of the Senior Secured Credit Facility to $465.0 million, net of an allowance for up to $75.0 million in outstanding letters of credit commitments. The increase was treated as a modification of debt under GAAP, and thus the Company recorded $0.6 million of new deferred financing fees in the consolidated financial statements. As of December 31, 2014, the Company had $455.1 million available under the revolving credit facility, net of $9.9 million in letters of credit. During 2014, the Company made one withdrawal and payment on the revolving credit facility as part of its debt management plans. The maximum amount outstanding at any time during the year on the revolving credit facility was $40.0 million, and the entire balance was repaid within the quarter it was borrowed. Revolving credit borrowings bear interest at a variable base rate plus an applicable margin based on the Company’s total leverage ratio. As of December 31, 2014, this rate would have been approximately 1.92%. In addition, there is an annual commitment fee, based on the Company’s total leverage ratio, which as of December 31, 2014, was equal to 0.25% of the average unused revolving credit borrowings available under the Senior Secured Credit Facility. Revolving credit borrowings are payable at the option of the Company throughout the term of the Senior Secured Credit Facility with the balance due in January 2019.
	The revolving portion of the Senior Secured Credit Facility requires the Company to maintain a specified maximum total senior secured leverage ratio of 5.50x when revolving loan commitments remain outstanding at the end of a fiscal quarter. On March 12, 2014, however, the revolving lenders holding a majority of the revolving loan commitments permanently waived and agreed that no event of default would result from any non-compliance so long as there were no revolving loans outstanding as of the last day of any fiscal quarter. As of December 31, 2014, the Company had no revolving loans outstanding; however the Company would have been in compliance with the maximum total senior secured leverage ratio, achieving a 2.42x ratio. Additionally within the terms of the Senior Secured Credit Facility, a senior secured leverage ratio at or below 3.50x results in the elimination of excess cash flow payments on the Senior Secured Credit Facility for the applicable year. The Senior Secured Credit Facility also provides certain financial incentives based on our total leverage ratio. A total leverage ratio at or below 4.00x results in a 25 basis point reduction to the applicable margin on the revolving credit facility, and a total leverage ratio at or below 3.50x results in a 12.5 basis point reduction to the revolving credit facility commitment fee and an additional 25 basis point reduction to the applicable margin on the revolving credit facility. A total leverage ratio at or below 3.25x results in a 25 basis point reduction to the applicable margin on our Term B-3 Loan. These reductions would remain in effect as long as the Company achieves a total leverage ratio at or below the related threshold. As of December 31, 2014, the total leverage ratio was 3.05x.
	In addition, the Senior Secured Credit Facility, among other things, includes customary restrictions (subject to certain exceptions) on the Company’s ability to incur certain indebtedness, grant certain liens, make certain investments, declare or pay certain dividends, or repurchase shares of the Company’s common stock. As of December 31, 2014, the Company is in compliance with all covenants under the Senior Secured Credit Facility.
	Senior Notes
	In May 2011, the Company completed an offering of $500.0 million of the 7.125% Senior Notes. The Company may from time to time seek to retire the 7.125% Senior Notes through cash purchases and/or exchanges for equity securities, in open market purchases, privately negotiated transactions, contractual redemptions or otherwise. Such repurchases or exchanges, if any, will depend on prevailing market conditions, liquidity requirements, contractual restrictions and other factors. The amounts involved may be material. Prior to May 15, 2015, the Company may redeem some or all of the 7.125% Senior Notes by paying the applicable “make-whole” premium. At any time on or after May 15, 2015, the Company may redeem some or all of the 7.125% Senior Notes at specified redemption prices in the governing indenture.
	The 7.125% Senior Notes are unsecured and guaranteed by the subsidiaries that guarantee the Senior Secured Credit Facility and will be unconditionally guaranteed, jointly and severally, by any future domestic subsidiaries that guarantee the Senior Secured Credit Facility. The indenture governing the 7.125% Senior Notes contains negative covenants restricting or limiting the Company’s ability to, among other things: incur or guarantee additional indebtedness, incur liens, pay dividends on, redeem or repurchase the Company’s capital stock, make certain investments, permit payment or dividend restrictions on certain of the Company’s subsidiaries, sell assets, engage in certain transactions with affiliates, and consolidate or merge or sell all or substantially all of the Company’s assets. Certain of these covenants would be suspended if the 7.125% Senior Notes were to reach investment grade.

DERIVATIVES

DERIVATIVES	12 Months Ended
	Dec. 31, 2014
DERIVATIVES	NOTE 8.	DERIVATIVES
	The Company is exposed to certain financial risk from volatility in interest rates, foreign exchange rates and commodity prices. The risk is managed through the use of financial derivative instruments including interest rate swaps, foreign currency forward contracts and commodity swaps. The Company’s current derivative instruments are used strictly as an economic hedge and not for speculative purposes. As necessary, the Company adjusts the values of the derivative instruments for counter-party or credit risk.
	Interest Rate
	The Company is subject to interest rate risk related to the Senior Secured Credit Facility and enters into interest rate swap contracts that are based on the LIBOR to manage a portion of this exposure. The Company has not elected hedge accounting treatment for these derivatives, and as a result, fair value adjustments are charged directly to Interest expense in the Consolidated Statements of Comprehensive Income. A summary of the Company’s interest rate derivatives as of December 31, 2014 and December 31, 2013 follows (dollars in millions):
			December 31, 2014								December 31, 2013
			Notional				Fair Value				Notional				Fair Value
			Amount								Amount
	3.75% Interest Rate Swap H, Aug 2011 – Aug 2014		$	—			$	—			$	350			$	(7.2	)
	3.77% Interest Rate Swap I, Aug 2011 – Aug 2014			—				—				350				(7.2	)
	2.96% Interest Rate Swap J, Aug 2013 – Aug 2014			—				—				125				(2.0	)
	3.05% Interest Rate Swap K, Aug 2013 – Aug 2014			—				—				125				(2.0	)
	3.44% Interest Rate Swap L, Aug 2016 – Aug 2019*			75				(2.3	)			75				(0.4	)
	3.43% Interest Rate Swap M, Aug 2016 – Aug 2019*			100				(3.0	)			100				(0.4	)
	3.37% Interest Rate Swap N, Aug 2016 – Aug 2019*			75				(2.1	)			75				(0.2	)
	3.19% Interest Rate Swap O, Aug 2016 – Aug 2019*			75				(1.7	)			75				0.2
	3.08% Interest Rate Swap P, Aug 2016 – Aug 2019*			75				(1.5	)			75				0.4
	2.99% Interest Rate Swap Q, Aug 2016 – Aug 2019*			50				(0.9	)			50				0.4
	2.98% Interest Rate Swap R, Aug 2016 – Aug 2019*			50				(0.9	)			50				0.4
	2.73% Interest Rate Swap S, Aug 2016 – Aug 2019*			50				(0.5	)			—				—
	2.74% Interest Rate Swap T, Aug 2016 – Aug 2019*			75				(0.8	)			—				—
	2.66% Interest Rate Swap U, Aug 2016 – Aug 2019*			50				(0.4	)			—				—
	2.60% Interest Rate Swap V, Aug 2016 – Aug 2019*			50				(0.3	)			—				—
	2.40% Interest Rate Swap W, Aug 2016 – Aug 2019*			25				0				—				—
	* includes LIBOR floor of 1.00%		$	750			$	(14.4	)		$	1,450.00			$	(18.0	)
	As of December 31, 2014, the Company did not have any interest rate derivatives subject to credit-risk or collateral requirement. As of December 31, 2013, certain of the Company’s interest rate derivatives contained credit-risk and collateral contingent features under which downgrades in the Company’s credit rating would have required the Company to increase its collateral. As of December 31, 2013, certain interest rate derivatives also contained provisions under which the Company was required to post additional collateral if the LIBOR interest rate curve reached certain levels.
	As of December 31, 2014 and December 31, 2013, the Company had recorded cash collateral of $0.0 million and $1.7 million, respectively, in Other current assets in the Condensed Consolidated Balance Sheets, as the balances are subject to frequent change.
	Currency Exchange
	The Company’s business is subject to foreign exchange rate risk. As a result, the Company enters into various forward rate contracts that qualify as derivatives under the authoritative accounting guidance to manage certain of these exposures. Forward contracts are used to hedge forecasted transactions and known exposure of payables denominated in a foreign currency. The Company generally has not elected to apply hedge accounting under the authoritative accounting guidance and recorded the unrealized fair value adjustments and realized gains and losses associated with these contracts in Other expense, net in the Consolidated Statements of Comprehensive Income during the period of change.
	The following table summarizes the outstanding foreign currency forward contracts as of December 31, 2014 and 2013 (amounts in millions):
			December 31, 2014								December 31, 2013
			Notional				Fair Value				Notional				Fair Value
			Amount								Amount
	Japanese Yen (JPY)		¥	300			$	(0.3	)		¥	600			$	(0.3	)
							$	(0.3	)						$	(0.3	)
	Commodity
	The Company’s business is subject to commodity price risk, primarily with component suppliers. As a result, the Company enters into various commodity swap contracts that qualify as derivatives under the authoritative accounting guidance to manage certain of these exposures. Swap contracts are used to hedge forecasted transactions either of the commodity or of components containing the commodity. The Company has not qualified for hedge accounting treatment for these commodity contracts, and as a result, unrealized fair value adjustments and realized gains and losses associated with these contracts were charged directly to Other expense, net in the Consolidated Statements of Comprehensive Income during the period of change.
	The following table summarizes the outstanding commodity swaps as of December 31, 2014 and December 31, 2013 (dollars in millions):
			December 31, 2014										December 31, 2013
			Notional				Quantity		Fair Value				Notional				Quantity	Fair Value
			Amount										Amount
	Aluminum		$	11.3			6,200 metric tons		$	(0.7	)		$	23.8			11,875 metric tons	$	(1.6	)
	Natural Gas		$	0.2			60,000 MMBtu			0			$	0.3			90,000 MMBtu		0
									$	(0.7	)							$	(1.6	)
	The following tabular disclosures further describe the Company’s derivative instruments and their impact on the financial condition of the Company (dollars in millions):
			December 31, 2014						December 31, 2013
			Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Derivatives not designated as hedging instruments
	Foreign currency contracts		Other current		$	(0.3	)		Other current		$	(0.3	)
			liabilities						liabilities
	Commodity contracts								Other current and			0.1
									non-current assets
			Other current and			(0.7	)		Other current and			(1.7	)
			non-current liabilities						non-current liabilities
	Interest rate contracts								Other non-			1.5
									current assets
			Other non-			(14.4	)		Other current and			(19.5	)
			current liabilities						non-current liabilities
	Total derivatives not designated as hedging instruments				$	(15.4	)				$	(19.9	)
	The fair values of the derivatives are recorded between Other current and non-current assets and Other current and non-current liabilities as appropriate in the Consolidated Balance Sheets. As of December 31, 2014, the amount recorded to Other current liabilities for foreign currency contracts was ($0.3) million. The amounts recorded to Other current and non-current liabilities for commodity contracts were ($0.6) million and ($0.1) million, respectively. The amounts recorded to Other non-current liabilities for interest rate contracts were ($14.4) million, respectively.
	As of December 31, 2013, the amount recorded to Other current liabilities for foreign currency contracts was ($0.3) million. The amounts recorded to Other current and non-current assets for commodity contracts were $0.1 million and $0.0 million, respectively. The amounts recorded to Other current and non-current liabilities for commodity contracts were ($1.5) million and ($0.2) million, respectively. The amount recorded to Other non-current assets for interest rate contracts was $1.5 million. The amounts recorded to Other current and non-current liabilities for interest rate contracts were ($18.5) million and ($1.0) million, respectively.
	The impact on the Company’s Consolidated Statements of Comprehensive Income related to foreign currency and commodity contracts can be found in NOTE 11, and the following tabular disclosure describes the location and impact on the Company’s results of operations related to unrealized gain (loss) on interest rate derivatives (dollars in millions):
			December 31,				December 31,				December 31,
			2014				2013				2012
	Location of impact on results of operations
Interest expense		$	3.5			$	34.3			$	25.5

PRODUCT_WARRANTY_LIABILITIES

PRODUCT WARRANTY LIABILITIES	12 Months Ended
	Dec. 31, 2014
PRODUCT WARRANTY LIABILITIES	NOTE 9.	PRODUCT WARRANTY LIABILITIES
	Product warranty liability activities consist of the following (dollars in millions):
			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	Beginning balance		$	90.5		$	109.7		$	115.4
	Payments			(35.0	)		(38.7	)		(47.3	)
	Increase in liability (warranty issued during period)			26.8			28.4			25.5
	Net adjustments to liability			0.7			(9.6	)		15.3
	Accretion (for Predecessor liabilities)			0.6			0.7			0.8
	Ending balance		$	83.6		$	90.5		$	109.7
	As of December 31, 2014, the current and non-current product warranty liabilities were $24.0 million and $59.6 million, respectively. As of December 31, 2013, the current and non-current product warranty liabilities were $37.4 million and $53.1 million, respectively.
	During June 2007, Old GM recognized the estimated cost of replacing the Dual Power Inverter Module (“DPIM”) used on H 40/50 EP hybrid systems. Certain units were falling short of their expected service life and Allison Transmission (the “Predecessor”), an operating unit of General Motors Corporation, decided to cover repair or replacement for an extended period. The Company is responsible for the first $12.0 million of qualified cost while General Motors Company (“GM”) is responsible for the next $34.0 million of costs, with any amount over $46.0 million being shared one-third by the Company and two-thirds by GM for shipments through June 30, 2009.
	During 2014, the Company completed an analysis of its DPIM extended coverage program and determined, based on current claims, that the product warranty liability should be increased by $3.9 million. This resulted in a $2.9 million increase in the GM DPIM receivable and a $1.0 million unfavorable adjustment to the Consolidated Statements of Comprehensive Income. As of December 31, 2014, the DPIM liability was $48.5 million with an associated receivable from GM of $28.7 million. Through December 31, 2014, the Company had paid approximately $32.8 million in DPIM claims and received approximately $14.9 million in reimbursement from GM. The Company will continue to review the total DPIM liability and GM receivable for any changes in estimates as additional data becomes available.
	During 2013, the Company completed an analysis of its DPIM extended coverage program and determined, based on current claims, that the product warranty liability should be reduced by $8.2 million. This resulted in a $5.8 million reduction in the GM DPIM receivable and a $2.4 million favorable adjustment to the Consolidated Statements of Comprehensive Income. As of December 31, 2013, the DPIM liability was $44.6 million with an associated receivable from GM of $25.8 million. Through December 31, 2013, the Company had paid approximately $25.5 million in DPIM claims and received approximately $9.1 million in reimbursement from GM.
	During 2012, the Company completed an analysis of its DPIM extended coverage program and determined, based on current claims, that the product liability should be reduced by $7.9 million. This resulted in a $7.3 million reduction in the GM DPIM receivable and a $0.6 million favorable adjustment to the Consolidated Statements of Comprehensive Income. As part of the analysis, it was also determined that design issues related to the early introduction of the replacement DPIM unit resulted in a $10.0 million increase to the product warranty liability. As the replacement DPIM unit is the responsibility of the Company and not covered by the asset purchase agreement dated June 28, 2007 (“Asset Purchase Agreement”), the Company recorded a $10.0 million charge to the Consolidated Statements of Comprehensive Income.
	The remaining adjustments to the total liability in 2014, 2013 and 2012 were the result of general changes in estimates for various products as additional claims data and field information became available.

DEFERRED_REVENUE

DEFERRED REVENUE	12 Months Ended
	Dec. 31, 2014
DEFERRED REVENUE	NOTE 10.	DEFERRED REVENUE
	As of December 31, 2014, the current and non-current deferred revenue for Extended Transmission Coverage (“ETC”) were $20.3 million and $48.7 million, respectively. As of December 31, 2013, the current and non-current deferred revenue for ETC were $20.4 million and $43.2 million, respectively.
	Deferred revenue for ETC activity (dollars in millions):
			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	Beginning balance		$	63.6		$	63.5		$	60.5
	Increases			26.2			21.1			22.9
	Revenue earned			(20.8	)		(21.0	)		(19.9	)
	Ending balance		$	69		$	63.6		$	63.5
	Deferred revenue recorded in current liabilities related to unearned net sales for defense contracts for the years ended December 31, 2014, 2013 and 2012 was approximately $0.3 million, $8.8 million and $0.7 million, respectively.
	Due to requests from the U.S. government, the Company billed, but did not ship certain tracked transmissions during 2013. Based on the lack of a fixed delivery date from the U.S. government, the Company deferred approximately $8.8 million of net sales for these transmissions until they were shipped in 2014.

OTHER_EXPENSE_NET

OTHER EXPENSE, NET	12 Months Ended
	Dec. 31, 2014
OTHER EXPENSE, NET	NOTE 11.	OTHER EXPENSE, NET
	Other expense, net consists of the following (dollars in millions):
			Years ended December 31,
			2014			2013			2012
	Loss on intercompany foreign exchange		$	(5.4	)	$	(2.3	)	$	—
	Grant program income			2.6			5.2			11.5
	Impairment loss on investments in technology-related initiatives			(2.0	)		(5.0	)		(14.4	)
	Gain on negotiation of commercial agreement			2			—			—
	Public offering fees and expenses			(1.4	)		(1.6	)		(6.1	)
	Unrealized gain (loss) on derivative contracts (see NOTE 8)			1.2			(1.5	)		0.9
	Realized loss on derivative contracts (see NOTE 8)			(1.0	)		(2.8	)		(1.3	)
	Loss on foreign exchange			(1.0	)		(2.4	)		(2.6	)
	Loss on repayments and repurchases of long-term debt (see NOTE 7)			(0.5	)		(0.8	)		(22.1	)
	Termination of services agreement			—			—			(16.0	)
	Loss on re-measurement of employee benefit plans (see NOTE 13)			—			—			(2.3	)
	Other			(0.1	)		0.3			(0.4	)
	Total		$	(5.6	)	$	(10.9	)	$	(52.8	)
	During 2014 and 2013, the Company recorded a loss of $5.4 and $2.3 million, respectively, resulting from intercompany financing transactions related to investments in plant assets for the Company’s India facility.
	During 2014, the Company fulfilled its obligations to the U.S. Department of Energy related to the development of hybrid-propulsion systems manufacturing capacity in the U.S. (the “Grant Program”). All applicable costs associated with the Grant Program have been charged to Engineering — research and development while the Government’s matching reimbursement was recorded to Other expense, net in the Consolidated Statements of Comprehensive Income.
	For the years ended December 31, 2014, 2013 and 2012, the Company made $2.0 million, $5.0 million and 14.4 million investments as part of an agreement to expand our position in transmission technologies. Due to various uncertainties surrounding the investments including, but not limited to, the startup nature of the underlying business, its continued negative cash flow, undercapitalization and unproven business plan, the Company has impaired the investments to zero as of December 31, 2014, 2013 and 2012.

OTHER_CURRENT_LIABILITIES

OTHER CURRENT LIABILITIES	12 Months Ended
	Dec. 31, 2014
OTHER CURRENT LIABILITIES	NOTE 12.	OTHER CURRENT LIABILITIES
	Other current liabilities consist of the following (dollars in millions):
			As of		As of
			December 31,		December 31,
			2014		2013
	Payroll and related costs		$	50.9	$	32.7
	Sales allowances			25.5		26.9
	Defense price reduction reserve			16.2		26.8
	Vendor buyback obligation			13.2		11.8
	Taxes payable			8.5		8.6
	Accrued interest payable			5.2		11.2
	Derivative liabilities			0.8		20.2
	Other accruals			11.4		14.1
	Total		$	131.7	$	152.3

EMPLOYEE_BENEFIT_PLANS

EMPLOYEE BENEFIT PLANS	12 Months Ended
	Dec. 31, 2014
EMPLOYEE BENEFIT PLANS	NOTE 13.	EMPLOYEE BENEFIT PLANS
	The Company’s hourly defined benefit pension plan generally provides benefits of negotiated, stated amounts for each year of service as well as significant supplemental benefits for employees who retire with 30 years of service before normal retirement age. For all hourly employees hired after May 18, 2008, the defined benefit pension plan was replaced with a defined contribution pension plan, and the company-sponsored retiree healthcare was also eliminated for those hired after May 18, 2008. The charge to expense for the hourly defined contribution pension plan was $1.3 million, $1.0 million and $0.9 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	In accordance with the Asset Purchase Agreement, the Company’s hourly employees who retired prior to October 2, 2011 (the “Cutoff Date”) will have their pension and OPEB paid by GM. The Company was required, pursuant to the Asset Purchase Agreement, to transfer pension assets to GM’s pension plan to cover the Company’s portion of its pension liability related to the employees who retired prior to the Cutoff Date. During the second quarter of 2012, the Company completed the transfer of its pension obligation for certain qualified hourly employees to GM’s pension plan. The transfer required a re-measurement of the hourly defined benefit pension plan resulting in a one-time non-cash settlement charge of $2.3 million recorded in Other expense, net in the Consolidated Statements of Comprehensive Income and a $4.2 million reduction to the Company’s pension liability with corresponding adjustments to AOCL, net of tax. This resulted in a $17.9 million gain to the Company’s 2011 actuarial valuation. Employees that retire subsequent to the Cutoff Date will have their Allison pension and OPEB paid by the Company and their GM pension benefit paid by GM.
	The Company’s salaried defined benefit plan covering salaried employees with a service date prior to January 1, 2001 is generally based on years of service and compensation history. The salaried defined contribution retirement savings plan requires the Company to match employee contributions up to certain predefined limits based upon eligible base salary. In addition to the matching contribution, the Company is required to make a contribution equal to 1% of eligible base salary for salaried employees with a service date on or after January 1, 1993 to cover certain benefits in retirement that are different from salaried employees with a service date prior to January 1, 1993. In addition, for salaried employees with a service date on or after January 1, 2001, the Company is required to contribute to its defined contribution retirement savings plan an amount equal to 4% of eligible base salary under the program. The charge to expense for the salaried defined contribution retirement savings plan was $5.4 million, $5.4 million and $5.1 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	The Company is also responsible for OPEB costs (medical, dental, vision, and life insurance) for hourly employees hired prior to May 19, 2008. Post-retirement benefit costs consist of service cost, interest cost on accrued obligations and the expected return on assets (calculated using a smoothed market value of assets). Any difference between actual and expected returns on assets during a year and actuarial gains and losses on liabilities together with any prior service costs are charged (or credited) to income over the average remaining service lives of employees. The benefit cost components shown in the Consolidated Statements of Comprehensive Income are based upon certain data specific to the Company, actuarial assumptions that were used for OPEB accounting disclosures, and certain allocation methodologies such as population demographics. The plan is unfunded and any future payments will be funded by the Company’s operating cash flows. As of December 31, 2014 and 2013, the Company had an estimated OPEB liability for hourly employees hired prior to May 19, 2008, excluding those employees eligible to retire at the time of the sale of the Company (“the Acquisition Transaction”), of $136.0 million and $120.7 million, respectively.
	As part of the Health Care Reform Act enacted in 2010, the Company has evaluated the impact on “High-cost Health Plans” in which employers offering health plan coverage exceeding certain thresholds must pay an excise tax equal to 40% of the value of the plan that exceeds the threshold amount. Although the excise tax does not come into effect until 2018, the Company has recorded $4.0 million in its OPEB liability as of December 31, 2014 with a corresponding adjustment to AOCL, net of tax.
	The Company provides contributions to certain international benefit plans; however, these contributions are not material for periods presented.
	For all pension and OPEB plans in which employees participate, costs are determined within the FASB’s authoritative accounting guidance set forth on employers’ defined benefit pensions including accounting for settlements and curtailments of defined benefit pension plans, termination of benefits and accounting for post-retirement benefits other than pensions. In accordance with the authoritative accounting guidance, the Company recognizes the funded status of its defined benefit pension plans and OPEB plan in its Consolidated Balance Sheets with a corresponding adjustment to AOCL, net of tax.
	Information about the net periodic benefit cost and other changes recognized in AOCL for the pension and post-retirement benefit plans is as follows (dollars in millions):
			Pension Plans									Post-retirement Benefits
			Year ended			Year ended			Year ended			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,			December 31,			December 31,			December 31,
			2014			2013			2012			2014			2013			2012
	Net Periodic Benefit Cost:
	Service cost		$	13.2		$	16.3		$	15.2		$	2.2		$	3.3		$	3.9
	Interest cost			5			4			4.1			5.9			5.8			7.2
	Expected return on assets			(7.7	)		(6.7	)		(5.9	)		—			—			—
	Prior service cost			0.1			0.1			0.1			(3.6	)		(3.6	)		—
	Loss (gain)			—			0.7			1.2			(0.7	)		—			—
	Settlement loss			—			—			2.3			—			—			—
	Net Periodic Benefit Cost		$	10.6		$	14.4		$	17		$	3.8		$	5.5		$	11.1
	Other changes recognized in other comprehensive income:
	Prior service credit		$	—		$	—		$	—		$	—		$	—		$	(28.9	)
	Net loss (gain)			2.1			(18.4	)		(2.1	)		7.8			(30.7	)		3.8
	Amortizations			(0.1	)		(0.8	)		(3.6	)		4.3			3.6			—
	Total recognized – other comprehensive income		$	2		$	(19.2	)	$	(5.7	)	$	12.1		$	(27.1	)	$	(25.1	)
	The table below provides the weighted-average actuarial assumptions used to determine the net periodic benefit cost.
			Pension Plans									Post-retirement Benefits
			Year ended			Year ended			Year ended			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,			December 31,			December 31,			December 31,
			2014			2013			2012			2014			2013			2012
	Discount rate			4.8	%		3.9	%		4.6	%		4.9	%		4.1	%		4.6	%
	Rate of compensation increase (salaried)			3	%		3	%		4	%		N/A			N/A			N/A
	Expected return on assets			6.8	%		7	%		7	%		N/A			N/A			N/A
	The table below provides the weighted-average actuarial assumptions used to determine the benefit obligations of the Company’s plans.
			Pension Plans						Post-retirement Benefits
			As of December 31,
			2014			2013			2014			2013
	Discount rate			3.9	%		4.8	%		4	%		4.9	%
	Rate of compensation increase (salaried)			3	%		3	%		N/A			N/A
	The Company’s pension and OPEB costs are calculated using various actuarial assumptions and methodologies as prescribed by authoritative accounting guidance. These assumptions include discount rates, expected return on plan assets, health care cost trend rates, inflation, rate of compensation increases, mortality rates and other factors. The Company reviews all actuarial assumptions on an annual basis.
	The discount rate is used to determine the present value of the Company’s benefit obligations. The Company’s discount rate is determined by matching the plans projected cash flows to a yield curve based on long-term, fixed income debt instruments available as of the measurement date of December 31, 2014.
	The overall expected rate of return on plan assets is based upon historical and expected future returns consistent with the expected benefit duration of the plan for each asset group adjusted for investment and administrative fees.
	During 2014, the Society of Actuaries finalized a new mortality table and a new mortality improvement scale that increased the anticipated longevity of life. As of December 31, 2014, as a result of the updated mortality assumption, the Company recorded an additional $2.9 million and $4.1 million in its defined benefit pension benefit obligation and OPEB obligation, respectively.
	Health care cost trends are used to project future post-retirement benefits payable from the Company’s plans. For the Company’s December 31, 2014 obligations, future post-retirement medical care costs were forecasted assuming an initial annual increase of 6.70%, decreasing to 4.50% by the year 2027. Future post-retirement prescription drug costs were forecasted assuming an initial annual increase of 6.00%, decreasing to 4.50% by the year 2027.
	As health care costs trends have a significant effect on the amounts reported, an increase and decrease of one-percentage-point would have the following effects in the year ended December 31, 2014 (dollars in millions):
			1% Increase			1% Decrease
	Effect on total of service and interest cost		$	1.7		$	(1.3	)
	Effect on post-retirement benefit obligation		$	28.6		$	(22.3	)
	The following table provides a reconciliation of the changes in the net benefit obligations and fair value of plan assets for the years ended December 31, 2014, 2013 and 2012 (dollars in millions):
			Pension Plans									Post-retirement Benefits
			Year ended			Year ended			Year ended			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,			December 31,			December 31,			December 31,
			2014			2013			2012			2014			2013			2012
	Benefit Obligations:
	Net benefit obligation at beginning of year		$	105.9		$	103.3		$	99.7		$	120.7		$	142.6		$	156.6
	Service cost			13.2			16.3			15.2			2.2			3.3			3.9
	Interest cost			5			4			4.1			5.9			5.8			7.2
	Plan Amendments			—			—			—			—			—			(28.9	)
	Settlements			—			—			(18.8	)		—			—			—
	Benefits paid			(1.5	)		(0.8	)		(0.4	)		(0.6	)		(0.3	)		—
	Actuarial loss (gain)			10.9			(16.9	)		3.5			7.8			(30.7	)		3.8
	Net benefit obligation at end of year		$	133.5		$	105.9		$	103.3		$	136		$	120.7		$	142.6
	Fair Value of Plan Assets:
Fair value of plan assets at beginning of year		$	108.6		$	89.4		$	83.4		$	—		$	—		$	—
Actual return on plan assets			16.4			8.2			11.5			—			—			—
Employer contributions			11.8			11.8			13.7			0.6			0.3			—
Settlements			—			—			(18.8	)		—			—			—
Benefits paid			(1.5	)		(0.8	)		(0.4	)		(0.6	)		(0.3	)		—
Fair value of plan assets at end of year		$	135.3		$	108.6		$	89.4		$	—		$	—		$	—
Net Funded Status		$	1.8		$	2.7		$	(13.9	)	$	(136.0	)	$	(120.7	)	$	(142.6	)
In the second quarter of 2012, the Company completed its negotiation with GM to determine the amount of pension assets to be transferred from the Company to GM as required by the Asset Purchase Agreement. The Company transferred $18.8 million of plan assets to GM to settle this obligation.
In the fourth quarter of 2012, the Company and the International Union, United Automobile, Aerospace and Agricultural Implement Workers of America (“UAW”) Local 933 entered into a new five year collective bargaining agreement that expires in November 2017. The multi-tiered wage and benefit structure from the prior agreement was retained and the parties agreed to additional changes, such as implementing a new retirement health care plan and eliminating the consumer price index based cost of living allowance that had been part of the prior agreement. As a result, the Company recorded a $28.9 million favorable adjustment to the net benefit obligation.
The Company’s pension plan assets consist of money market funds, mutual funds and listed equities. The Company’s valuation techniques used to fair value pension plan assets represents a market approach in active markets for identical assets that qualifies as Level 1 in the fair value hierarchy.
The fair values of plan assets for the Company’s pension plans as of December 31, 2014 and 2013 are as follows (dollars in millions):
		Quoted Prices in Active Markets
		for Identical Assets (Level 1)
		2014						2013
Asset Category		Fair Value			%			Fair Value			%
Cash and cash equivalents		$	8.6			6	%	$	3.6			3	%
Diversified equity securities			57.8			43			51.5			48
Diversified debt securities			68.9			51			53.5			49
Total		$	135.3			100	%	$	108.6			100	%
The Company’s investment strategy with respect to pension plan assets is to invest the assets in accordance with laws and regulations. The long-term primary objectives for the Company’s pension assets are to provide results that meet or exceed the plans’ actuarially assumed long-term rate of return without subjecting the funds to undue risk. To achieve these objectives the Company has established the following targets:
		Target
Asset Category		Hourly			Salary
Cash and cash equivalents			5	%		8	%
Diversified equity securities			39			46
Diversified debt securities			56			46
Total			100	%		100	%
Through 2014, the Company’s investment committee has continued to evaluate the investments and take steps toward the established targets.
The following table discloses the amounts recognized in the balance sheet and in AOCL at December 31, 2014 and 2013, on a pre-tax basis (dollars in millions):
		Pension Plans						Post-retirement Benefits
		As of December 31,
		2014			2013			2014			2013
Amounts Recognized in Balance Sheet:
Noncurrent assets		$	7.9		$	7.4		$	—		$	—
Current liabilities			—			—			(1.2	)		(1.4	)
Noncurrent liabilities			(6.1	)		(4.7	)		(134.8	)		(119.3	)
Total asset (liability)		$	1.8		$	2.7		$	(136.0	)	$	(120.7	)
Accumulated Other Comprehensive Loss:
Prior service (cost) credit		$	(0.1	)	$	(0.2	)	$	21.7		$	25.4
Actuarial gain			0.6			2.7			8.6			17.1
Total		$	0.5		$	2.5		$	30.3		$	42.5
The amounts in AOCL expected to be amortized and recognized as a component of net periodic benefit cost in 2015 are as follows (dollars in millions):
		2015
		Pension			Post-retirement
		Plans			Benefits
Prior service (cost) credit		$	(1.0	)	$	3.6
Actuarial loss			1			—
Total		$	0		$	3.6
The accumulated benefit obligation for the Company’s pension plans as of December 31, 2014 and 2013 was $129.7 million and $103.1 million, respectively.
As of December 31, 2014 and 2013, the projected benefit obligation, the accumulated benefit obligation, and the fair value of plan assets for pension plans with a projected benefit obligation in excess of plan assets and for pension plans with an accumulated benefit obligation in excess of plan assets were as follows (dollars in millions):
		Hourly Plan						Salary Plan
		As of December 31,
		2014			2013			2014			2013
Plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation			N/A	1		N/A	1	$	71.4		$	53.8
Fair value of plan assets			N/A	1		N/A	1	$	65.3		$	49.1
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation			N/A	1		N/A	1	$	67.6		$	50.9
Fair value of plan assets			N/A	1		N/A	1	$	65.3		$	49.1
1	As of December 31, 2014 and 2013, the hourly defined benefit pension plan had plan assets greater than both the projected benefit obligation and accumulated benefit obligation.
Information about expected cash flows for the Company’s pension and post-retirement benefit plans is as follows (dollars in millions):
		Pension			Post-retirement
		Plans			Benefits
Employer Contributions:
2015 expected contributions		$	2		$	1.2
Expected Benefit Payments:
2015			2.3			1.2
2016			3			1.7
2017			3.8			2.4
2018			4.6			3.2
2019			5.5			3.9
2020-2024			40.6			27.7
Expected benefit payments for pension and post-retirement benefits will be paid from plan trusts or corporate assets. The Company’s funding policy is to contribute amounts annually that are at least equal to the amounts required by applicable laws and regulations or to directly fund payments to plan participants. Additional discretionary contributions will be made when deemed appropriate to meet the Company’s long-term obligation to the plans.
In June 2012, the Company established a non-qualified deferred compensation plan (“Deferred Compensation Plan”) for a select group of management. Under the terms of the plan, the Company has utilized a rabbi trust to accumulate assets to fund its promise to pay benefits under the Deferred Compensation Plan. The rabbi trust is an irrevocable trust, which restricts any use of funds (operational or otherwise) by the Company other than to pay benefits under the Deferred Compensation Plan, and prevents immediate taxation of contributed amounts. Funds are accumulated through both employee deferrals and a company match. Funds can be invested by the employee into a diversified group of investment options, which have been selected by the Company’s investment committee, that are all categorized as Level 1 in the fair value hierarchy. The company match resulted in a charge of $0.2 million, $0.3 million, and $0.1 million to the Consolidated Statements of Comprehensive Income for the years ended December 31, 2014, 2013 and 2012, respectively, and the fair value of the rabbi trust plan assets and deferred compensation obligation was $2.9 million and $1.3 million as of December 31, 2014 and 2013, respectively.

STOCKBASED_COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2014
STOCK-BASED COMPENSATION	NOTE 14.	STOCK-BASED COMPENSATION
	In March 2012, the Company’s Board of Directors adopted and the Company’s stockholders approved the Allison Transmission Holdings, Inc. 2011 Equity Incentive Award Plan (“2011 Plan”), which became effective as of the day prior to the consummation of the Company’s initial public offering. Under the 2011 Plan, certain employees (including executive officers), consultants and directors are eligible to receive equity-based compensation, including non-qualified stock options, incentive stock options, restricted stock, dividend equivalents, stock payments, restricted stock units (“RSU”), performance awards, stock appreciation rights and other equity-based awards, or any combination thereof. The 2011 Plan limits the aggregate number of shares of common stock available for issue to 15.3 million and will expire on, and no option or other equity award may be granted pursuant to the 2011 Plan after, the tenth anniversary of the date the 2011 Plan was approved by the Board of Directors.
	Prior to the adoption of the 2011 Plan, the Company’s equity-based awards were granted under the Equity Incentive Plan of Allison Transmission Holdings, Inc. (“Prior Plan”). As of the effective date of the 2011 Plan, no new awards will be granted under the Prior Plan, but the Prior Plan will continue to govern the equity awards issued under the Prior Plan.
	Restricted Stock Units
	RSUs were issued to certain employees in 2014, 2013 and 2012, and certain directors in 2014 and 2013 under the 2011 Plan at fair market value at the date of grant. These awards entitle the holder to receive one common share for each RSU upon vesting, which generally occurs over either one, two or three years upon continued performance of services by the RSU holders. A summary of RSU activity as of December 31, 2014, 2013 and 2012, and changes during the period then ended is presented below:
	Non-vested RSUs:		RSUs			Weighted-Average
			(in millions)			Grant-Date
						Fair Value
	Non-vested as of December 31, 2011			—		$	—
	Granted			1			20.2
	Vested			—			—
	Forfeited			—			—
	Non-vested as of December 31, 2012			1		$	20.2
	Granted			0.2			23.31
	Vested			(0.4	)		20.23
	Forfeited			—			—
	Non-vested as of December 31, 2013			0.8		$	20.9
	Granted			0			29.85
	Vested			(0.6	)		20.32
	Forfeited			—			—
	Non-vested as of December 31, 2014			0.2		$	26.57
	As of December 31, 2014 and 2013, there were $3.0 million and $10.4 million, respectively, of unrecognized compensation cost related to non-vested RSU compensation arrangements granted under the 2011 Plan. This cost is expected to be recognized, on a straight line basis, over a period of approximately two years. RSU incentive compensation expense recorded was $9.8 million, $12.0 million and $0.9 million for the years ended December 31, 2014, 2013 and 2012, respectively. The total fair value of RSUs vested during the years ended December 31, 2014, 2013 and 2012 was approximately $20.2 million, $9.0 million and $0.0 million, respectively.
	Pursuant to the share withholding provisions of the 2011 Plan and the related RSU award agreement, certain employees, in lieu of paying withholding taxes on the vesting of RSUs, authorized the withholding of an aggregate of approximately 0.3 million and 0.1 million shares, respectively of the Company’s common stock to satisfy their minimum statutory tax withholding requirements related to such vesting events during 2014 and 2013. The withheld shares were recorded as a reduction to equity on the applicable vesting dates of approximately $8.4 million and $3.6 million during 2014 and 2013, respectively.
	Restricted Stock
	Restricted stock was granted to certain employees in 2014 under the 2011 Plan at fair market value on the date of grant. The restrictions lapse upon continued performance by the restricted stock holders on the vest date which generally occurs over one, two or three years. A summary of restricted stock activity as of December 31, 2014 and changes during the period then ended is presented below:
	Non-vested Shares:		Restricted			Weighted-Average
			Stock			Grant-Date Fair
			(in millions)			Value
	Non-vested as of December 31, 2013			—		$	—
	Granted			0.2			29.47
	Vested			—			—
	Forfeited			—			—
	Non-vested as of December 31, 2014			0.2		$	29.47
	As of December 2014, there was $3.4 million of unrecognized compensation cost related to non-vested restricted stock compensation arrangements granted under the 2011 Plan. This cost is expected to be recognized, on a straight line basis, over a period of approximately 2 years. Restricted stock incentive compensation expense recorded was $1.6 million for the year ended December 31, 2014.
	Stock Options
	Stock options granted under the Prior Plan after the completion of the Acquisition Transaction and through March 2012, have a per share exercise price based on the fair market value of the Company at the date of grant. Stock options granted under the 2011 Plan have a per share exercise price based on the closing price of a share of the Company’s common stock as reported by the NYSE on the date of grant. All stock options expire 10 years after the grant date. The options vest upon the continued performance of services by the option holder over time, with either 20% or 33% of the award vesting on each anniversary of the grant date over three to five years for awards under the Prior Plan and 100% in December of the year that is two years after the year of grant under the 2011 Plan. Upon termination of employment for reasons other than cause, retirement before the age of 65 with less than 90 points (calculated as age plus years of service), death or disability, the options shall cease to be exercisable ninety days following the date of the optionees’ termination of service. Upon termination of employment for cause, the options shall not be exercisable on the date of such termination. Upon termination of employment for retirement at or after the age of 65, the options shall cease to be exercisable three years following such date. Upon termination of employment for retirement before the age of 65 with 90 or more points, the options shall cease to be exercisable two years following such date. Upon termination of employment for death or disability, the options shall cease to be exercisable twelve months following such date.
	In accordance with the FASB’s authoritative accounting guidance on stock compensation, each option grant is to be recorded at fair value. When options are granted, the Company uses a Black-Scholes option pricing model to calculate the fair value of each option award using the assumptions noted in the following table:
			2014			2013			2012
	Expected volatility			38	%		51	%		N/A
	Expected dividend yield			1.6	%		1.2	%		N/A
	Expected term (in years)			5.5			5.4			N/A
	Expected forfeitures			0	%		0	%		N/A
	Risk-free rate			1.7	%		1.6	%		N/A
	Expected volatility is based on “the average volatilities of otherwise similar public entities” as defined by authoritative accounting guidance. The Company currently pays a $0.15 dividend per quarter. The expected term is derived from the average of the weighted vesting life and the contractual term. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant.
	A summary of option activity as of December 31, 2014, 2013 and 2012, and changes during the period then ended is presented below:
			Options			Weighted-			Weighted-Average
			(in millions)			Average Exercise			Remaining
						Price			Contractual Term
	Outstanding as of December 31, 2011			14.9		$	13.4			4.94 years
	Exercisable as of December 31, 2011			11.5		$	13.37			4.88 years
	Granted			—			—
	Exercised			(2.7	)		—
	Forfeited or expired			(0.3	)		—
	Outstanding as of December 31, 2012			11.9		$	14.01			4.93 years
	Exercisable as of December 31, 2012			11.8		$	14.02			4.91 years
	Granted			0.6		$	23.39
	Exercised			(3.8	)		—
	Forfeited or expired			—			—
	Outstanding as of December 31, 2013			8.7		$	15.33			4.30 years
	Exercisable as of December 31, 2013			8.1		$	14.79			3.94 years
	Granted			0.4		$	30.23
	Exercised			(4.2	)		—
	Forfeited or expired			—			—
	Outstanding as of December 31, 2014			4.9		$	17.49			4.19 years
Exercisable as of December 31, 2014			3.9		$	15.32			3.08 years
The weighted-average grant-date fair value of options granted during the years ended December 31, 2014, 2013 and 2012 was $9.51, $9.76 and $0.0, respectively. The total fair value of stock options vested during the years ended December 31, 2014, 2013 and 2012 was $0.0 million, $0.7 million and $7.5 million, respectively. The total intrinsic value of stock options exercised during the years ended December 31, 2014, 2013 and 2012 was $82.3 million, $58.0 million and $24.6 million, respectively. The aggregate intrinsic value of stock options outstanding and exercisable was $80.4 million and $72.5 million as of December 31, 2014, and $106.8 million and $103.8 million as of December 31, 2013, respectively.
A summary of the status of the Company’s non-vested stock options as of December 31, 2014, 2013 and 2012, and changes during the period ended December 31, 2014, 2013 and 2012 is presented below:
Non-vested Stock Options:		Options			Weighted-Average
		(in millions)			Grant-Date
					Fair Value
Non-vested at December 31, 2011			3.4		$	2.81
Granted			—			—
Vested			(2.9	)		2.58
Forfeited			(0.3	)		4
Non-vested at December 31, 2012			0.2		$	4.34
Granted			0.6			9.76
Vested			(0.2	)		3.59
Forfeited			—			—
Non-vested at December 31, 2013			0.6		$	9.06
Granted			0.4			9.51
Vested			—			—
Forfeited			—			—
Non-vested at December 31, 2014			1		$	9.44
As of December 31, 2014, 2013 and 2012, there was $4.8 million, $4.2 million and $0.5 million, respectively, of unrecognized compensation cost related to non-vested stock option compensation arrangements granted under the Prior Plan and the 2011 Plan. This cost is expected to be recognized, on a straight line basis, over a period of approximately two years. Stock option incentive compensation expense recorded was $3.3 million, $1.7 million and $5.5 million for the years ended December 31, 2014, 2013 and 2012, respectively.

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2014
INCOME TAXES	NOTE 15.	INCOME TAXES
	Income before income taxes included the following (dollars in millions):
			Years ended December 31,
			2014			2013			2012
	U.S. income		$	355.1		$	259		$	204.1
	Foreign income			13			7.1			12.1
	Total		$	368.1		$	266.1		$	216.2
	The provision for income tax expense (benefit) was estimated as follows (dollars in millions):
			Years ended December 31,
			2014			2013			2012
	Estimated current income taxes:
	U.S. federal		$	1.6		$	0.2		$	1.5
	Foreign			6.3			1.9			3.9
	U.S. state and local			(0.2	)		0.6			0.4
	Total Current			7.7			2.7			5.8
	Deferred income tax expense (credit), net:
	U.S. federal			125.6			87.6			(282.5	)
	Foreign			(0.3	)		0.1			0.1
	U.S. state and local			6.5			10.3			(21.4	)
	Total Deferred			131.8			98			(303.8	)
	Total income tax expense (benefit)		$	139.5		$	100.7		$	(298.0	)
	Cash paid for income taxes for the years ended December 31, 2014, 2013 and 2012 was $5.0 million, $3.8 million and $10.7 million, respectively.
	A reconciliation of the provision for income tax expense (benefit) compared with the amounts at the U.S. federal statutory rate is as follows (dollars in millions):
			Years ended December 31,
			2014			2013			2012
	Tax at U.S. statutory income tax rate		$	128.9		$	93.1		$	75.7
	Foreign rate differential			(2.3	)		(0.7	)		(2.6	)
	Non-deductible expenses			3.9			0.8			4.2
	Valuation allowance			2.6			1			(384.1	)
	State tax expense			4			7.3			5.7
	Adjustment to deferred tax expense			2.4			(0.3	)		2.2
	Other adjustments			(0.0	)		(0.5	)		0.9
	Total income tax expense (benefit)		$	139.5		$	100.7		$	(298.0	)
	The Company has not recognized any deferred tax liabilities associated with investments and earnings in foreign subsidiaries as they are intended to be permanent in duration. Such amounts may become taxable upon an actual or deemed repatriation in the future; however, at this time, management believes any related unrecognized deferred tax liability is immaterial.
	Temporary differences and carryforwards that gave rise to deferred tax assets and liabilities included the following (dollars in millions):
			As of			As of
			December 31,			December 31,
			2014			2013
	Deferred tax assets:
	Inventories		$	5.1		$	4.6
	Warranty accrual			30.5			32.7
	Sales allowances and rebates			6.7			7.9
	Deferred revenue			25.7			24
	Post-retirement health care			5.7			—
	Intangibles			77.3			83.6
	Other accrued liabilities			32.7			27.2
	Unrealized loss on interest rate derivatives			5.7			3.7
	Operating loss carryforwards			107.8			140.7
	Stock based compensation			6.9			12.5
	Technology-related investments			6.6			6.8
	Loan fees			—			0.9
	Other			16.4			10.4
	Total Deferred tax assets			327.1			355
	Valuation allowances			(5.2	)		(2.8	)
	Deferred tax liabilities:
	Property, plant and equipment			(20.2	)		(22.0	)
	Goodwill			(320.8	)		(280.3	)
	Trade name			(90.3	)		(60.6	)
	Product warranty liabilities			(4.3	)		(5.6	)
	Pension			—			(0.5	)
	Post-retirement health care			—			(0.2	)
	Other			(3.5	)		—
	Total Deferred tax liabilities			(439.1	)		(369.2	)
	Net Deferred tax liability		$	(117.2	)	$	(17.0	)
Of the estimated net operating loss carryforwards as of December 31, 2014, approximately 91% relates to U.S. federal net operating loss carryforwards and approximately 9% relates to the U.S. state net operating loss carryforwards. Substantially all U.S. Federal and State operating loss carryforwards will not expire until 2027-2032. As of December 31, 2014, the Company had $253.3 million of net operating loss carryforwards for U.S. federal income tax purposes. If the Company continues to generate taxable income, it expects to utilize the remaining U.S. federal net operating loss carryforwards as early as the first quarter of 2016.
Management has determined, based on an evaluation of available objective and subjective evidence, that it is more likely than not that certain foreign deferred tax assets will not be realized and therefore continue to offset these deferred tax assets with a valuation allowance of $5.2 million and $2.8 million as of December 31, 2014 and 2013, respectively.
In accordance with the FASB’s authoritative guidance on accounting for uncertainty in income taxes, the Company has recorded a liability for unrecognized tax benefits related to the 2010 Research & Development Credit. The accounting guidance prescribes a recognition threshold and measurement attributes for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. Management does not anticipate any significant changes in the balance within the coming year. All of the Company’s returns (when filed) will remain subject to examination by the various taxing authorities for the duration of the applicable statute of limitations (generally three years from the earlier of the date of filing or the due date of the return). The change in the liability for unrecognized tax benefits are as follows (dollars in millions):
December 31, 2012		$	—
December 31, 2013		$	2.3
Increases in unrecognized tax benefits as a result of current year activity			0.2
December 31, 2014		$	2.5
For the years ended December 31, 2014, 2013 and 2012, the Company recognized no interest and penalties in the Consolidated Statements of Comprehensive Income. The Company follows a policy of recording any tax related interest or penalties in Income tax expense.

OTHER_COMPREHENSIVE_LOSS

OTHER COMPREHENSIVE LOSS	12 Months Ended
	Dec. 31, 2014
OTHER COMPREHENSIVE LOSS	NOTE 16.	OTHER COMPREHENSIVE LOSS
	The changes in components of accumulated other comprehensive loss consisted of the following (dollars in millions):
			Before Tax			Tax (Expense)			After Tax
						Benefit
	Balance at December 31, 2011		$	(33.2	)	$	(23.8	)	$	(57.0	)
	Foreign currency translation			(0.7	)		—			(0.7	)
	Pension and OPEB liability adjustment			26.7			(11.6	)		15.1
	Available-for-sale securities			(2.0	)		0.7			(1.3	)
	Net current period other comprehensive loss		$	24		$	(10.9	)	$	13.1
	Balance at December 31, 2012		$	(9.2	)	$	(34.7	)	$	(43.9	)
	Foreign currency translation			(5.0	)		—			(5.0	)
	Pension and OPEB liability adjustment			46.4			(17.4	)		29
	Available-for-sale securities			(1.9	)		0.8			(1.1	)
	Net current period other comprehensive income		$	39.5		$	(16.6	)	$	22.9
	Balance at December 31, 2013		$	30.3		$	(51.3	)	$	(21.0	)
	Foreign currency translation			(7.4	)		—			(7.4	)
	Pension and OPEB liability adjustment			(14.6	)		5.5			(9.1	)
	Available-for-sale securities			(3.2	)		1.2			(2.0	)
	Net current period other comprehensive loss		$	(25.2	)	$	6.7		$	(18.5	)
	Balance at December 31, 2014		$	5.1		$	(44.6	)	$	(39.5	)
	The following table shows the location in the Consolidated Statements of Comprehensive Income affected by reclassifications from AOCL (dollars in millions):
			For the year ended December 31, 2014
	AOCL Components		Amount			Affected line item in the consolidated
			reclassified from			statements of comprehensive income
			AOCL
	Amortization of defined benefit pension items:
	Prior service cost		$	3.2		Cost of sales
				0.3		Selling, general and
						administrative
				0.1		Engineering – research and
						development
	Actuarial loss			0.7		Cost of sales
				(0.0	)	Selling, general and
						administrative
				(0.0	)	Engineering – research and
						development
	Total reclassifications, before tax			4.3		Income before income
						taxes
	Income tax expense			(1.6	)	Tax expense
	Total reclassifications		$	2.7		Net of tax
	Prior service cost and actuarial loss are included in the computation of the Company’s net periodic benefit cost. Please see NOTE 13 for additional details.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2014
COMMITMENTS AND CONTINGENCIES	NOTE 17.	COMMITMENTS AND CONTINGENCIES
	Operating Leases
	The Company leases certain facilities under various operating leases. Rent expense under the non-cancelable operating leases was $5.4 million, $5.7 million, and $5.5million for the years ended December 31, 2014, 2013 and 2012, respectively. Certain leases contain renewal options.
	As of December 31, 2014, future payments under non-cancelable operating leases are as follows over each of the next five years and thereafter (dollars in millions):
	2015		$	4.6
	2016			2.8
	2017			1.7
	2018			0.8
	2019			0.6
	Thereafter			2
	Total		$	12.5
	Claims, Disputes, and Litigation
	The Company is party to various legal actions and administrative proceedings and subject to various claims arising in the ordinary course of business. These proceedings primarily involve commercial claims, product liability claims, personal injury claims and workers’ compensation claims. The Company believes that the ultimate liability, if any, in excess of amounts already provided for in the consolidated financial statements or covered by insurance on the disposition of these matters will not have a material adverse effect on the financial position, results of operations or cash flows of the Company.

CONCENTRATION_OF_RISK

CONCENTRATION OF RISK	12 Months Ended
	Dec. 31, 2014
CONCENTRATION OF RISK	NOTE 18.	CONCENTRATION OF RISK
	As of December 31, 2014 and 2013, the Company employed approximately 2,700 employees, respectively with 90% of those employees in the U.S. Approximately 60% of the Company’s U.S. employees were represented by unions and subject to a collective bargaining agreement as of December 31, 2014 and 2013. In addition, many of the hourly employees outside the U.S. are represented by various unions. The Company is currently operating under a collective bargaining agreement with the UAW Local 933 that expires in November 2017.
	Three customers accounted for greater than 10% of net sales within the last three years presented.
			Years ended December 31,
	% of net sales		2014			2013			2012
	Daimler AG			17	%		17	%		13	%
	Navistar, Inc.			10	%		10	%		11	%
	Oshkosh Corporation			4	%		8	%		11	%
	No other customers accounted for more than 10% of net sales of the Company during the years ended December 31, 2014, 2013 or 2012.
	Three customers accounted for greater than 10% of outstanding accounts receivable within the last two years presented.
	% of accounts receivable		As of			As of
			December 31,			December 31,
			2014			2013
	Daimler AG			15	%		15	%
	Navistar, Inc.			12	%		10	%
	AB Volvo.			8	%		11	%
	No other customers accounted for more than 10% of the outstanding accounts receivable as of December 31, 2014 or December 31, 2013.
	One supplier accounted for greater than 10% of materials purchased for the periods presented:
			Years ended December 31,
	% of material purchased		2014			2013			2012
	Linamar Corporation Inc.			10	%		13	%		13	%
	No other supplier accounted for more than 10% of materials purchased during the years ended December 31, 2014, 2013 or 2012.

CERTAIN_RELATIONSHIPS_AND_RELA

CERTAIN RELATIONSHIPS AND RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2014
CERTAIN RELATIONSHIPS AND RELATED PARTY TRANSACTIONS	NOTE 19.	CERTAIN RELATIONSHIPS AND RELATED PARTY TRANSACTIONS
	Investment funds affiliated with the Sponsors sold their common stock through a series of public offerings from March 2012 through September 2014. As of December 31, 2014, investment funds affiliated with the Sponsors no longer own any shares of the Company’s outstanding common stock. Pursuant to an amended and restated stockholders agreement, a majority of the Board of Directors had previously been designated by the Sponsors; however, as a result of their no longer owning any shares of the Company’s common stock, the Sponsors no longer have the right to designate members of the Board of Directors.
	Senior Notes Held by Executive Officers
	As of December 31, 2014, Lawrence E. Dewey, our Chairman, President and Chief Executive Officer, and David S. Graziosi, our Executive Vice President, Chief Financial Officer and Treasurer, held approximately $100,000 and $450,000, respectively, in aggregate principal amount of the 7.125% Senior Notes.
	Repurchase of Common Stock held by Sponsors
	During 2014, the Company completed four secondary public offerings in September, June, April and February of 5,392,499, 40,250,000, 25,000,000, and 28,750,000 shares of its common stock held by investment funds affiliated with the Sponsors at public offering prices, less underwriting discounts and commissions, of $30.46, $29.95, $29.78 and $29.17 per share, respectively. In connection with certain of the offerings, the Company repurchased from the underwriters 5,000,000 shares in June 2014 and 3,428,179 shares in February 2014 at the prices paid by the underwriters and subsequently retired those shares.
	During 2013, the Company completed three secondary public offerings in August, November and December of 23,805,000, 15,000,000 and 12,500,000 shares of its common stock held by investment funds affiliated with the Sponsors at a public offering price, less underwriting discounts and commissions, of $21.18, $23.10 and $25.56 per share, respectively. In connection with the offering in August, the Company repurchased from the underwriters 4,700,000 shares of the 23,805,000 shares at the price paid by the underwriters and subsequently retired those shares.

COMMON_STOCK

COMMON STOCK	12 Months Ended
	Dec. 31, 2014
COMMON STOCK	NOTE 20.	COMMON STOCK
	The Company’s current stock repurchase program was announced on October 30, 2014. The Board authorized management to repurchase up to $500.0 million of its common stock on the open market or through privately negotiated transactions through December 31, 2016. The timing and amount of stock purchases are subject to market conditions and corporate needs. This stock repurchase program may be extended, modified, suspended or discontinued at any time at the Company’s discretion. As of December 31, 2014, $500.0 million remained available for stock repurchases under the repurchase program.

EARNINGS_PER_SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2014
EARNINGS PER SHARE	NOTE 21.	EARNINGS PER SHARE
	The Company presents both basic and diluted earnings per share (“EPS”) amounts. Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the reporting period. Diluted EPS is calculated by dividing net income by the weighted average number of common shares and common equivalent shares outstanding during the reporting period that are calculated using the treasury stock method for stock-based awards. The treasury stock method assumes that the Company uses the proceeds from the exercise of awards to repurchase common stock at the average market price during the period. The assumed proceeds under the treasury stock method include the purchase price that the grantee will pay in the future, compensation cost for future service that the Company has not yet recognized and any tax benefits that would be credited to additional paid-in-capital when the award generates a tax deduction. If there would be a shortfall resulting in a charge to additional paid-in-capital, such an amount would be a reduction of the proceeds to the extent of the gains. The diluted weighted-average common shares outstanding exclude the anti-dilutive effect of certain stock options since such options had an exercise price in excess of the monthly average market value of our common stock. As of December 31, 2014, there were no outstanding anti-dilutive stock options.
	The following table reconciles the numerators and denominators used to calculate basic EPS and diluted EPS (in millions, except per share data):
			Years ended December 31,
			2014		2013		2012
	Net income		$	228.6	$	165.4	$	514.2
	Weighted average shares of common stock outstanding			179.8		184.5		182
	Dilutive effect stock-based awards			2.5		3.4		4.2
	Diluted weighted average shares of common stock outstanding			182.3		187.9		186.2
	Basic earnings per share attributable to common stockholders		$	1.27	$	0.9	$	2.83
	Diluted earnings per share attributable to common stockholders		$	1.25	$	0.88	$	2.76

GEOGRAPHIC_INFORMATION

GEOGRAPHIC INFORMATION	12 Months Ended
	Dec. 31, 2014
GEOGRAPHIC INFORMATION	NOTE 22.	GEOGRAPHIC INFORMATION
	The Company had the following net sales by country as follows (dollars in millions):
			Years ended December 31,
			2014		2013		2012
	United States		$	1,578.00	$	1,354.30	$	1,509.60
	China			128.7		141		136.4
	Canada			85.1		88.6		123
	Japan			45.8		37		52
	Germany			38.1		53.9		39.1
	United Kingdom			36.8		42.5		74.1
	Other			214.9		209.5		207.6
	Total		$	2,127.40	$	1,926.80	$	2,141.80
	The Company had net long-lived assets by country as follows (dollars in millions):
			Years ended December 31,
			2014		2013		2012
	United States		$	442.6	$	478.7	$	493.6
	India			51.5		59.9		76.8
	Hungary			15.1		18.1		18.4
	Others			5.4		6.7		7.4
	Total		$	514.6	$	563.4	$	596.2

QUARTERLY_FINANCIAL_INFORMATIO

QUARTERLY FINANCIAL INFORMATION	12 Months Ended
	Dec. 31, 2014
QUARTERLY FINANCIAL INFORMATION	NOTE 23. QUARTERLY FINANCIAL INFORMATION
	The following is a summary of the unaudited quarterly results of operations. The Company believes that all adjustments considered necessary for a fair presentation in accordance with GAAP have been included (unaudited, in millions, except per share data).
		Quarters ended,
		March 31		June 30		September 30		December 31
	2014
	Net sales	$	493.6	$	536.1	$	553.3	$	544.4
	Gross profit		222.5		238.5		259.3		255.6
	Operating income		114.8		132.2		147.3		117.8
	Income before income taxes		79.3		94.7		116.3		77.8
	Net income		52.1		57.2		68.8		50.5
	Basic earnings per share	$	0.29	$	0.32	$	0.38	$	0.28
	Diluted earnings per share	$	0.28	$	0.31	$	0.38	$	0.28
	2013
	Net sales	$	457.4	$	512.1	$	466.3	$	491
	Gross profit		198.3		226.1		206.1		211.4
	Operating income		81.4		117.7		111.2		99.6
	Income before income taxes		44.4		81.8		72.4		67.5
	Net income		27.5		50.5		44.5		42.9
	Basic earnings per share	$	0.15	$	0.27	$	0.24	$	0.24
	Diluted earnings per share	$	0.15	$	0.26	$	0.24	$	0.23

Schedule_IParent_Company_only_

Schedule I-Parent Company only Balance Sheets	12 Months Ended
	Dec. 31, 2014
Schedule I-Parent Company only Balance Sheets	Allison Transmission Holdings, Inc.
	Schedule I—Parent Company only Balance Sheets
	(dollars in millions)
		December 31,			December 31,
		2014			2013
	ASSETS
	Current Assets:
	Cash	$	—		$	—
	Total Current Assets		—			—
	Investments in and advances to subsidiaries		1,397.80			1,438.80
	TOTAL ASSETS	$	1,397.80		$	1,438.80
	LIABILITIES AND STOCKHOLDERS’ EQUITY
	Current Liabilities:
	Accounts payable	$	—		$	—
	Total Current Liabilities		—			—
	Capital stock		1.8			1.8
	Additional paid-in-capital		1,651.00			1,631.80
	Treasury stock		—			—
	Accumulated deficit		(215.5	)		(173.8	)
	Accumulated other comprehensive loss, net of tax		(39.5	)		(21.0	)
	TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$	1,397.80		$	1,438.80
	The accompanying note is an integral part of the Parent Company only financial statements.
	Allison Transmission Holdings, Inc.
	Schedule I—Parent Company only Statements of Comprehensive Income
	(dollars in millions)
		Years ended December 31,
		2014			2013			2012
	Net sales	$	—		$	—		$	—
	General and administrative fees		—			—			—
	Total operating income		—			—			—
	Other income:
	Equity earnings of consolidated subsidiary		228.6			165.4			514.2
	Income before income taxes		228.6			165.4			514.2
	Income tax expense		—			—			—
	Net income	$	228.6		$	165.4		$	514.2
	Comprehensive income	$	228.6		$	165.4		$	514.2
	The accompanying note is an integral part of the Parent Company only financial statements.
	Allison Transmission Holdings, Inc.
	Schedule I—Parent Company only Statements of Cash Flows
	(dollars in millions)
		Years ended December 31,
		2014			2013			2012
	CASH FLOWS FROM OPERATING ACTIVITIES:
	Net income	$	228.6		$	165.4		$	514.2
	Deduct items included in net income not providing cash:
	Equity in earnings in consolidated subsidiary		(228.6	)		(165.4	)		(514.2	)
	Net cash provided by operating activities		—			—			—
	CASH FLOWS FROM INVESTING ACTIVITIES:
	Investments in subsidiaries		(59.6	)		(46.3	)		(29.0	)
	Dividends		91.6			77.1			32.8
	Net cash provided by investing activities		32			30.8			3.8
	CASH FLOWS FROM FINANCING ACTIVITIES:
	Capital contributions		59.6			46.3			29
	Dividends		(91.6	)		(77.1	)		(32.8	)
	Net cash used in financing activities		(32.0	)		(30.8	)		(3.8	)
	Net increase (decrease) during period		—			—			—
	Cash and cash equivalents at beginning of period		—			—			—
	Cash and cash equivalents at end of period	$	—		$	—		$	—
	The accompanying note is an integral part of the Parent Company only financial statements.
	Allison Transmission Holdings, Inc.
	Schedule I—Parent Company only Footnote
	NOTE 1—BASIS OF PRESENTATION
	Allison Transmission Holdings, Inc. (the “Parent Company”) is a holding company that conducts all of its business operations through its subsidiaries. There are restrictions on the Parent Company’s ability to obtain funds from its subsidiaries through dividends (refer to NOTE 7 of the Consolidated Financial Statements). The entire amount of our consolidated net assets was subject to restrictions on payment of dividends at the end of December 31, 2014, 2013 and 2012. Accordingly, these financial statements have been presented on a “parent-only” basis. Under a parent-only presentation, the Parent Company’s investments in its consolidated subsidiaries are presented under the equity method of accounting. These parent-only financial statements should be read in conjunction with Allison Transmission Holdings, Inc.’s audited Consolidated Financial Statements included elsewhere herein.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2014
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation
	The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The information herein reflects all normal recurring material adjustments, which are, in the opinion of management, necessary for the fair statements of the results for the periods presented. The consolidated financial statements herein consist of all wholly-owned domestic and foreign subsidiaries with all significant intercompany transactions eliminated.
	These consolidated financial statements present the financial position, results of comprehensive income, cash flows and statements of equity. Certain immaterial reclassifications have been made in the consolidated financial statements of prior periods to conform to the current period presentation. These reclassifications have no impact on previously reported net income, total stockholders’ equity or cash flows.
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities and the reported amounts of revenue and expenses. Significant estimates include, but are not limited to, allowance for doubtful accounts, sales allowances, government price adjustments, fair market values and future cash flows associated with goodwill, indefinite-life intangibles, long-lived asset impairment tests, useful lives for depreciation and amortization, warranty liability, determination of discount and other assumptions for pension and other postretirement benefit expense, income taxes and deferred tax valuation allowances, derivative valuation, and contingencies. The Company’s accounting policies involve the application of judgments and assumptions made by management that include inherent risks and uncertainties. Actual results could differ materially from these estimates. Changes in estimates are recorded in results of operations in the period that the events or circumstances giving rise to such changes occur.
Segment Reporting	Segment Reporting
	In accordance with the Financial Accounting Standards Board (“FASB”) authoritative accounting guidance on segment reporting, the Company has one operating segment and reportable segment. The Company is in one line of business, which is the manufacture and distribution of fully-automatic transmissions.
Government Grants	Government Grants
	The Company recognizes government grants when there is reasonable assurance that the Company will comply with the conditions attached to the grant arrangement and the funds will be received. When the government grants relate to reimbursement of costs, the grant income is recognized in Other expense, net in the Consolidated Statements of Comprehensive Income. When the government grants relate to a reimbursement of capital expenditures, the grants are recognized as a reduction of the basis of the assets in the Consolidated Balance Sheets.
Cash and Cash Equivalents	Cash and Cash Equivalents
	Cash equivalents are defined as short-term, highly-liquid investments with original maturities of 90 days or less. Under the Company’s cash management system, checks issued but not presented to banks may result in book overdraft balances for accounting purposes and are classified within Accounts payable in the Consolidated Balance Sheets. The change in book overdrafts is reported as a component of operating cash flows for Accounts payable.
Marketable Securities	Marketable Securities
	The Company determines the appropriate classification of all marketable securities as “held-to-maturity,” “available-for-sale” or “trading” at the time of purchase, and re-evaluates such classifications as of each balance sheet date. As of December 31, 2014, the Company’s marketable securities are classified as either available-for-sale or trading.
	Available-for-sale securities are carried at fair value with the unrealized gain or loss reported in Accumulated other comprehensive loss (“AOCL”). Unrealized gains or losses considered to be “other-than-temporary” are recognized in income. Trading securities are carried at fair value with the unrealized gain or loss recognized in Other expense, net. The fair value of the Company’s investment securities is determined by currently available market prices. See NOTE 6 for more details.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts
	The allowance for doubtful trade accounts receivable reflects estimated losses to be incurred in the collection of the receivables. Estimated losses are based on historical collection experience as well as a review by management of the current status of all receivables. Account balances are charged against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote.
Inventories	Inventories
	Inventories are stated at the lower of cost or market. The Company determines cost using the first-in, first-out method. The Company analyzes inventory on a quarterly basis to determine whether it is excess or obsolete inventory. Any decline in carrying value of estimated excess or obsolete inventory is recorded as a reduction of inventory and as an expense included in Cost of sales in the period it is identified.
Property, Plant and Equipment	Property, Plant and Equipment
	Property, plant and equipment are recorded at cost less accumulated depreciation. Depreciation expense is recorded using the straight-line method over the following estimated lives:
		Range in Years
	Land improvements	5 – 30
	Buildings and building improvements	10 – 40
	Machinery and equipment	2 – 20
	Software	2 – 5
	Special tools	2 – 10
	Software represents the costs of software developed or obtained for internal use. Software costs are amortized on a straight-line basis over their estimated useful lives. Software assets are reviewed for impairment when events or circumstances indicate that the carrying value may not be recoverable over the remaining lives of the assets. Upgrades and enhancements are capitalized if they result in added functionality, which enables the software to perform tasks it was previously incapable of performing. Software maintenance, training, data conversion and business process reengineering costs are expensed in the period in which they are incurred.
	Special tooling represents the costs to design and develop tools, dies, jigs and other items owned by the Company and used in the manufacture of components by suppliers under long-term supply agreements. Special tooling is depreciated over the tool’s expected life. Special tooling used in the development of new technology is expensed as incurred. Engineering, testing and other costs incurred in the design and development of production parts are expensed as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	The carrying value of long-lived assets is evaluated whenever events or circumstances indicate that the carrying value of an asset may not be recoverable. Events or circumstances that would result in an impairment review primarily include a significant change in the use of an asset, or the planned sale or disposal of an asset. The asset would be considered impaired when there is no future use planned for the asset or the future net undiscounted cash flows generated by the asset or asset group are less than its carrying value. An impairment loss would be recognized based on the amount by which the carrying value exceeds fair value.
	Assumptions and estimates used to determine cash flows in the evaluation of impairment and the fair values used to determine the impairment are subject to a degree of judgment and complexity. Any changes to the assumptions and estimates resulting from changes in actual results or market conditions from those anticipated may affect the carrying value of long-lived assets and could result in an impairment charge.
	As a result of events and circumstances in the fourth quarter of 2014, the Company reviewed certain of its long-lived assets related to the production of the H3000 and H4000 hybrid-propulsion systems, resulting in a $15.4 million loss recorded for the year ended December 31, 2014. The loss, determined by using future net discounted cash flows, included approximately $1.7 million of accrued expenses related to the impairment of the long-lived assets. Deteriorating market conditions for hybrid-propulsion vehicles, principally as a result of decreased fuel costs, alternative fuels and other technologies, significantly contributed to the future cash flows of the related assets being less than the carrying value of those assets.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets
	Goodwill represents the excess of purchase price paid over the fair value of net assets acquired. In accordance with the FASB’s authoritative accounting guidance on goodwill, the Company does not amortize goodwill but rather evaluates it for impairment on an annual basis, or more often if events or circumstances change that could cause goodwill to become impaired. Goodwill is tested for impairment at the reporting unit level, which is the same as the Company’s one operating and reportable segment. The Company has elected to perform its annual impairment test on October 31 of every year. A multi-step impairment test is performed on goodwill. In Step 0, the Company has the option to evaluate various qualitative factors to determine the likelihood of impairment. If determined that the fair value is more likely than not less than the carrying value, then the Company is required to perform Step 1. If the Company does not elect to perform Step 0, it can voluntarily proceed directly to Step 1. In Step 1, the Company performs a quantitative analysis to compare the fair value of its reporting unit to its carrying value including goodwill. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not considered impaired, and the Company is not required to perform further testing. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then the Company must perform Step 2 of the impairment test in order to determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, then the Company would record an impairment loss equal to the difference.
	Goodwill impairment testing for 2014 was performed by assessing certain qualitative trends and factors. The Company’s qualitative assessment included an assessment of business changes, economic outlook, financial trends and forecasts, growth rates, credit ratings, equity ratings, discount rates, industry data and other relevant qualitative factors. Events or circumstances that could unfavorably impact the key assumptions include lower net sales driven by market conditions, our inability to execute on marketing programs and/or delay in the introduction of new products, lower gross margins as a result of market conditions or failure to obtain forecasted cost reductions, or a higher discount rate as a result of market conditions. While unpredictable and inherently uncertain, the Company believes its forecast estimates are reasonable and incorporate assumptions that similar market participants would use in their estimates of fair value. These trends and factors were compared to, and based on, the assumptions used in the quantitative assessment performed in 2013. After reviewing various qualitative factors, the Company’s 2014 annual goodwill impairment test indicated that the fair value of the reporting unit more likely than not exceeded its carrying value, indicating no impairment.
	Other intangible assets have both indefinite and finite useful lives. Intangible assets with indefinite useful lives, such as the Company’s trade name, are not amortized but are tested annually for impairment. The Company has elected to perform our annual trade name impairment test on October 31 of every year and follow a similar multi-step impairment test that is performed on goodwill. After reviewing various qualitative factors, the Company’s 2014 annual trade name impairment test indicated that the fair value of the trade name more likely than not exceeded its carrying value, indicating no impairment. The qualitative review included an assessment of various key assumptions and factors including, among others, an assessment of business changes, economic outlooks, financial trends and forecasts, royalty savings rates, credit ratings, equity ratings and discount rates. Events or circumstances that could unfavorably impact the key assumptions include lower net sales driven by market conditions, our inability to execute on marketing programs and/or delay in introduction of new products, and higher discount rate as a result of market conditions. While unpredictable and inherently uncertain, we believe the forecast estimates are reasonable and incorporate those assumptions that similar market participants would use in their estimates of fair value. These trends and factors were compared to, and based on, the assumptions used in the quantitative assessment performed in 2013. After reviewing various qualitative factors, the fair value of trade name exceeded the respective carrying value.
	Intangible assets with finite lives are amortized over their estimated useful lives and reviewed for impairment when circumstances change that would create a triggering event. Customer relationships are amortized over the life in which expected benefits are to be consumed. The other remaining finite useful life intangibles are amortized on a straight-line basis over their useful lives. The Company evaluates the remaining useful life of the other intangible assets on a periodic basis to determine whether events or circumstances warrant a revision to the remaining useful life. Assumptions and estimates about future values and remaining useful lives of the Company’s intangible and other long-lived assets are complex and subjective. They can be affected by a variety of factors, including external factors such as industry and economic trends, and internal factors, such as changes in the Company’s business strategy and internal forecasts. Although management believes the historical assumptions and estimates are reasonable and appropriate, different assumptions and estimates could materially impact the Company’s reported financial results.
	NOTE 5 provides further information on Goodwill and Other intangible assets.
Deferred Financing Costs	Deferred Financing Costs
	Deferred financing costs are stated at cost as a component of other non-current assets and amortized over the life of the related debt using the effective interest method. Amortization of deferred financing costs is recorded as part of interest expense and totaled $8.1 million, $10.9 million and $14.5 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Financial Instruments	Financial Instruments
	The Company’s cash equivalents are invested in U.S. Government backed securities and recorded at fair value in the Consolidated Balance Sheets. The carrying values of accounts receivable and accounts payable approximate fair value due to their short-term nature. The Company’s financial derivative instruments, including interest rate swaps and foreign currency and commodity forward contracts are carried at fair value on the Consolidated Balance Sheets. Refer to NOTE 6 for more detail. The Company’s long-term debt obligations are carried at historical amounts with the Company providing fair value disclosure in NOTE 7.
Insurable Liabilities	Insurable Liabilities
	The Company records liabilities for its medical, workers’ compensation, long-term disability, product, general and auto liabilities. The determination of these liabilities and related expenses is dependent on claims experience. For most of these liabilities, claims incurred but not yet reported are estimated based upon historical claims experience.
Revenue Recognition	Revenue Recognition
	The Company records sales when title has transferred to the customer, there is evidence of an agreement, the sales price is fixed or determinable, delivery has occurred or services have been rendered, and collectability is reasonably assured. The Company sells Extended Transmission Coverage (“ETC”) for which sales are deferred. ETC sales are recognized ratably over the period of the ETC, which typically ranges from two to five years after initial sale. Costs associated with ETC programs are recorded as incurred during the extended period. Distributor and customer sales incentives, consisting of allowances and other rebates, are estimated at the time of sale based upon the Company’s history and experience and are recorded as a reduction to Net sales. Incentive programs are generally product specific or region specific. Some factors used in estimating the cost of incentives include the number of transmissions that will be affected by the incentive program and rate of acceptance of any incentive program. If the actual number of affected transmissions differs from this estimate, or if a different mix of incentives is actually paid, the impact on Net sales would be recorded in the period that the change was identified. Consideration given to commercial customers recorded as a reduction of Net sales in the Consolidated Statements of Comprehensive Income included $66.9 million, $65.2 million, and $59.9 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Sales under U.S. government production contracts are recorded when the product is accepted, title has transferred to the U.S. government, the sales price is fixed or determinable, and delivery has occurred. Deferred revenue arises from cash received in advance of the culmination of the earnings process and is recognized as revenue in future periods when the applicable revenue recognition criteria have been met. Under the terms of the U.S. government contracts, there are certain price reduction clauses and provisions for potential price reductions which are estimated at the time of sale based upon the Company’s history and experience and are recorded as a reduction to Net sales. Potential reductions may be attributed to a change in projected sales volumes or plant efficiencies which impact overall costs. As of December 31, 2014 and 2013, the Company had $63.1 million and $49.6 million recorded in the price reduction reserve account, respectively.
	Due to requests from the U.S. government, the Company billed, but did not ship certain tracked transmissions during 2013. Based on the lack of a fixed delivery date from the U.S. government, the Company deferred approximately $8.8 million of net sales for these transmissions until they were shipped in 2014. See NOTE 10 for additional details.
	The Company classifies shipping and handling billed to customers in Net sales and shipping and handling costs in Cost of sales, in accordance with authoritative accounting guidance.
	The Company contracts with various third parties to provide engineering services. These services are recorded as Net sales in accordance with the terms of the contract. The saleable engineering recorded was $7.4 million, 12.4 million and $7.8 million for the years ended December 31, 2014, 2013 and 2012, respectively. The associated costs are recorded in Cost of sales.
Warranty	Warranty
	Provisions for estimated expenses related to product warranties are made at the time products are sold. Warranty claims arise when a transmission fails while in service during the relevant warranty period. The warranty reserve is adjusted in Selling, general and administrative expenses based on the Company’s current and historical warranty claims paid and associated repair costs. These estimates are established using historical information including the nature, frequency, and average cost of warranty claims and are adjusted as actual information becomes available. From time to time, the Company may initiate a specific field action program. As a result of the uncertainty surrounding the nature and frequency of specific field action programs, the liability for such programs is recorded when the Company commits to an action. The Company reviews and assesses the liability for these programs on a quarterly basis. The Company also assesses its ability to recover certain costs from its suppliers and records a receivable from the supplier when it believes a recovery is probable.
Research and Development	Research and Development
	The Company incurs costs in connection with research and development programs that are expected to contribute to future earnings. Such costs are charged to Engineering — research and development as incurred.
Foreign Currency Translation	Foreign Currency Translation
	Most of the subsidiaries outside the United States prepare financial statements in currencies other than the U.S. dollar. The functional currency for all these subsidiaries is the local currency, except for the Company’s Hong Kong and Middle East subsidiaries which currently use the U.S. dollar as their functional currency. Balances are translated at period-end exchange rates for assets and liabilities and monthly weighted-average exchange rates for revenues and expenses. The translation gains (losses) are stated as a component of AOCL as disclosed in NOTE 16.
Derivative Instruments	Derivative Instruments
	In the normal course of business, the Company is exposed to fluctuations in interest rates, foreign currency exchange rates, and commodity prices. The risk is managed through the use of financial derivative instruments including interest rate swaps and commodity and foreign currency forward contracts. Despite the fact that the Company either has not elected or does not qualify for hedge accounting treatment on all of its derivative instruments, the contracts are used strictly as an economic hedge and not for speculative purposes. As necessary, the Company adjusts the values of the derivative instruments for counter-party or credit risk. NOTE 8 provides further information on the accounting treatment of the Company’s derivative instruments.
Income Taxes	Income Taxes
	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the expected future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The future tax benefits associated with operating loss and tax credit carryforwards are recognized as deferred tax assets. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled.
	The need to establish a valuation allowance against the deferred tax assets is assessed periodically based on a more-likely-than-not realization threshold, in accordance with the FASB’s authoritative accounting guidance on income taxes. Appropriate consideration is given to all positive and negative evidence related to that realization. This assessment considers, among other matters, the nature, frequency and severity of recent losses, forecasts of future profitability, the duration of statutory carryforward periods, and experience with tax attributes expiring unused and tax planning alternatives. The weight given to these considerations depends upon the degree to which they can be objectively verified.
Stock-Based Compensation	Stock-Based Compensation
	The Company maintains a stock-based compensation plan which allows employees (including executive officers), consultants and directors to receive equity awards. The Company has adopted the FASB’s authoritative accounting guidance on share-based payments and recognizes the fair value of the awards as compensation expense over the vesting period. The accounting guidance also requires that forfeitures be estimated over the vesting period of an award instead of being recognized as a reduction of compensation expense when the forfeiture actually occurs.
Pension and Post-retirement Benefit Plans	Pension and Post-retirement Benefit Plans
	For pension and other post-retirement benefits (“OPEB”) plans in which employees participate, costs are determined within the FASB’s authoritative accounting guidance set forth in employers’ defined benefit pensions including accounting for settlements and curtailments of defined benefit pension plans, termination of benefits and accounting for post-retirement benefits other than pensions. In accordance with the authoritative accounting guidance, the Company recognizes the funded status of its defined benefit pension plans and OPEB plan in its Consolidated Balance Sheets with a corresponding adjustment to AOCL, net of tax.
	Post-retirement benefit costs consist of service cost, interest cost on accrued obligations and the expected return on assets (calculated using a smoothed market value of assets). Any difference between actual and expected returns on assets during a year and actuarial gains and losses on liabilities together with any prior service costs are charged (or credited) to income over the average remaining service lives of employees.
	The benefit cost components shown in the Consolidated Statements of Comprehensive Income are based upon various actuarial assumptions and methodologies as prescribed by authoritative accounting guidance. These assumptions include discount rates, expected return on plan assets, health care cost trend rates, inflation, rate of compensation increases, population demographics, mortality rates and other factors. The Company reviews all actuarial assumptions on an annual basis. Changes in key economic indicators can change these assumptions. These assumptions, along with the actual value of assets at the measurement date, will impact the calculation of pension expenses for the year. For instance, the effect of a one percentage point decrease in the assumed discount rate would result in an increase in the December 31, 2014 defined benefit pension plans obligation of approximately $20.0 million. Similarly, a one percentage point decrease in the assumed discount rate would result in an increase in the December 31, 2014 OPEB obligation of approximately $23.7 million.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements
	In August 2014, the FASB issued authoritative accounting guidance on the disclosure of uncertainties about an entity’s ability to continue as a going concern. The guidance requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that financial statements are available to be issued when applicable) and to provide related footnote disclosures. The guidance is effective prospectively for fiscal years beginning after December 15, 2016, but can be early-adopted. While the adoption of this guidance is not expected to have an effect on the Company’s consolidated financial statements, it could affect the disclosure applied under these circumstances in the future.
	In May 2014, the FASB issued authoritative accounting guidance on a company’s accounting for revenue from contracts with customers. The guidance applies to all companies that enter into contracts with customers to transfer goods, service or nonfinancial assets. The guidance requires these companies to 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 or services. The guidance also requires improved disclosures regarding the nature, timing, amount and uncertainty of revenue that is recognized. The guidance is effective prospectively for fiscal years beginning after December 15, 2016. Management is currently assessing the potential impact of the adoption of this guidance on the Company’s consolidated financial statements.

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2014
Property And Equipment Estimated Useful Lives	Depreciation expense is recorded using the straight-line method over the following estimated lives:
		Range in Years
	Land improvements	5 – 30
	Buildings and building improvements	10 – 40
	Machinery and equipment	2 – 20
	Software	2 – 5
	Special tools	2 – 10

INVENTORIES_Tables

INVENTORIES (Tables)	12 Months Ended
	Dec. 31, 2014
Components of Inventories	Inventories consisted of the following components (dollars in millions):
		December 31,		December 31,
		2014		2013
	Purchased parts and raw materials	$	72.3	$	79.7
	Work in progress		6.1		5.7
	Service parts		46.5		45.8
	Finished goods		18.6		29.2
	Total inventories	$	143.5	$	160.4

PROPERTY_PLANT_AND_EQUIPMENT_T

PROPERTY, PLANT AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2014
Property Plant and Equipment Cost and Accumulated Depreciation	The cost and accumulated depreciation of property, plant and equipment are as follows (dollars in millions):
		December 31,			December 31,
		2014			2013
	Land and land improvements	$	23.6		$	20.3
	Buildings and building improvements		281.6			271.4
	Machinery and equipment		576.2			567.7
	Software		117			112.9
	Special tools		143.6			143.4
	Construction in progress		39.9			48.6
	Total property, plant and equipment		1.181.9			1,164.30
	Accumulated depreciation		(667.3	)		(600.9	)
	Property, plant and equipment, net	$	514.6		$	563.4

GOODWILL_AND_OTHER_INTANGIBLE_1

GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Other Intangible Assets	The following presents a summary of other intangible assets (dollars in millions):
		December 31, 2014							December 31, 2013
		Intangible		Accumulated			Intangible		Intangible		Accumulated			Intangible
		assets, gross		amortization			assets, net		assets, gross		amortization			assets, net
	Other intangible assets:
	Trade name	$	870	$	—		$	870	$	870	$	—		$	870
	Customer relationships - defense		62.3		(27.9	)		34.4		62.3		(24.4	)		37.9
	Customer relationships - commercial		831.8		(426.9	)		404.9		831.8		(374.9	)		456.9
	Proprietary technology		476.3		(282.0	)		194.3		476.3		(243.9	)		232.4
	Non-compete agreement		17.3		(12.8	)		4.5		17.3		(11.1	)		6.2
	Patented technology - defense		28.2		(24.5	)		3.7		28.2		(21.2	)		7
	Tooling rights		4.5		(4.3	)		0.2		4.5		(4.1	)		0.4
	Patented technology - commercial		260.6		(260.6	)		—		260.6		(260.6	)		—
	Total	$	2,551.00	$	(1,039.0	)	$	1,512.00	$	2,551.00	$	(940.2	)	$	1,610.80
Amortization Expense Related to Other Intangible Assets for Next Five Years and Thereafter	Amortization expense related to other intangible assets for the next five years and thereafter is expected to be (dollars in millions):
		2015		2016			2017		2018		2019			Thereafter
	Amortization expense	$	97.1	$	92.4		$	89.7	$	87.2	$	85.7		$	189.9

FAIR_VALUE_OF_FINANCIAL_INSTRU1

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Fair Value of Financial Assets and (Liabilities)	The following table summarizes the fair value of the Company’s financial assets and (liabilities) as of December 31 (dollars in millions):
		Fair Value Measurements Using
		Quoted Prices in Active						Significant Other						TOTAL
		Markets for Identical						Observable Inputs (Level 2)
		Assets (Level 1)
		2014			2013			2014			2013			2014			2013
	Cash equivalents	$	55		$	5		$	—		$	—		$	55		$	5
	Available-for-sale securities		8.6			8.2			—			—			8.6			8.2
	Rabbi trust assets		2.9			1.3			—			—			2.9			1.3
	Deferred compensation obligation		(2.9	)		(1.3	)		—			—			(2.9	)		(1.3	)
	Derivative assets		—			—			0			1.6			0			1.6
	Derivative liabilities		—			—			(15.4	)		(21.4	)		(15.4	)		(21.4	)
	Total	$	63.6		$	13.2		$	(15.4	)	$	(19.8	)	$	48.2		$	(6.6	)

DEBT_Tables

DEBT (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Long-Term Debt and Maturities	Long-term debt and maturities are as follows (dollars in millions):
		December 31,		December 31,
		2014		2013
	Long-term debt:
	Senior Secured Credit Facility Term B-2 Loan, variable, due 2017	$	283.6	$	423.5
	Senior Secured Credit Facility Term B-3 Loan, variable, due 2019		1,765.60		1,783.50
	Senior Notes, fixed 7.125%, due 2019		471.3		471.3
	Total long-term debt	$	2,520.50	$	2,678.30
	Less: current maturities of long-term debt		17.9		17.9
	Total long-term debt less current portion	$	2,502.60	$	2,660.40
Principal Payments Required on Long Term Debt	Principal payments required on long-term debt during the next five years are as follows:
		Required Principal Payments
	(dollars in millions)	2015		2016		2017		2018		2019
	Payment	$	17.9	$	17.9	$	301.4	$	17.9	$	2,165.40

DERIVATIVES_Tables

DERIVATIVES (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Company's Interest Rate Derivatives	A summary of the Company’s interest rate derivatives as of December 31, 2014 and December 31, 2013 follows (dollars in millions):
		December 31, 2014								December 31, 2013
		Notional				Fair Value				Notional				Fair Value
		Amount								Amount
	3.75% Interest Rate Swap H, Aug 2011 – Aug 2014	$	—			$	—			$	350			$	(7.2	)
	3.77% Interest Rate Swap I, Aug 2011 – Aug 2014		—				—				350				(7.2	)
	2.96% Interest Rate Swap J, Aug 2013 – Aug 2014		—				—				125				(2.0	)
	3.05% Interest Rate Swap K, Aug 2013 – Aug 2014		—				—				125				(2.0	)
	3.44% Interest Rate Swap L, Aug 2016 – Aug 2019*		75				(2.3	)			75				(0.4	)
	3.43% Interest Rate Swap M, Aug 2016 – Aug 2019*		100				(3.0	)			100				(0.4	)
	3.37% Interest Rate Swap N, Aug 2016 – Aug 2019*		75				(2.1	)			75				(0.2	)
	3.19% Interest Rate Swap O, Aug 2016 – Aug 2019*		75				(1.7	)			75				0.2
	3.08% Interest Rate Swap P, Aug 2016 – Aug 2019*		75				(1.5	)			75				0.4
	2.99% Interest Rate Swap Q, Aug 2016 – Aug 2019*		50				(0.9	)			50				0.4
	2.98% Interest Rate Swap R, Aug 2016 – Aug 2019*		50				(0.9	)			50				0.4
	2.73% Interest Rate Swap S, Aug 2016 – Aug 2019*		50				(0.5	)			—				—
	2.74% Interest Rate Swap T, Aug 2016 – Aug 2019*		75				(0.8	)			—				—
	2.66% Interest Rate Swap U, Aug 2016 – Aug 2019*		50				(0.4	)			—				—
	2.60% Interest Rate Swap V, Aug 2016 – Aug 2019*		50				(0.3	)			—				—
	2.40% Interest Rate Swap W, Aug 2016 – Aug 2019*		25				0				—				—
	* includes LIBOR floor of 1.00%	$	750			$	(14.4	)		$	1,450.00			$	(18.0	)
Derivative Instruments and their Impact on the Financial Condition	The following tabular disclosures further describe the Company’s derivative instruments and their impact on the financial condition of the Company (dollars in millions):
		December 31, 2014						December 31, 2013
		Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Derivatives not designated as hedging instruments
	Foreign currency contracts	Other current		$	(0.3	)		Other current		$	(0.3	)
		liabilities						liabilities
	Commodity contracts							Other current and			0.1
								non-current assets
		Other current and			(0.7	)		Other current and			(1.7	)
		non-current liabilities						non-current liabilities
	Interest rate contracts							Other non-			1.5
								current assets
		Other non-			(14.4	)		Other current and			(19.5	)
		current liabilities						non-current liabilities
	Total derivatives not designated as hedging instruments			$	(15.4	)				$	(19.9	)
Interest Rate Derivative Instruments and their Impact on the Results of Operations	The impact on the Company’s Consolidated Statements of Comprehensive Income related to foreign currency and commodity contracts can be found in NOTE 11, and the following tabular disclosure describes the location and impact on the Company’s results of operations related to unrealized gain (loss) on interest rate derivatives (dollars in millions):
		December 31,				December 31,				December 31,
		2014				2013				2012
	Location of impact on results of operations
	Interest expense	$	3.5			$	34.3			$	25.5
Foreign Currency Forward Contract
Notional Amount and Fair Value of Derivatives	The following table summarizes the outstanding foreign currency forward contracts as of December 31, 2014 and 2013 (amounts in millions):
		December 31, 2014								December 31, 2013
		Notional				Fair Value				Notional				Fair Value
		Amount								Amount
	Japanese Yen (JPY)	¥	300			$	(0.3	)		¥	600			$	(0.3	)
						$	(0.3	)						$	(0.3	)
Commodity contracts
Notional Amount and Fair Value of Derivatives	The following table summarizes the outstanding commodity swaps as of December 31, 2014 and December 31, 2013 (dollars in millions):
		December 31, 2014										December 31, 2013
		Notional				Quantity		Fair Value				Notional				Quantity	Fair Value
		Amount										Amount
	Aluminum	$	11.3			6,200 metric tons		$	(0.7	)		$	23.8			11,875 metric tons	$	(1.6	)
	Natural Gas	$	0.2			60,000 MMBtu			0			$	0.3			90,000 MMBtu		0
								$	(0.7	)							$	(1.6	)

PRODUCT_WARRANTY_LIABILITIES_T

PRODUCT WARRANTY LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2014
Product Warranty Liability Activities	Product warranty liability activities consist of the following (dollars in millions):
		Year ended			Year ended			Year ended
		December 31,			December 31,			December 31,
		2014			2013			2012
	Beginning balance	$	90.5		$	109.7		$	115.4
	Payments		(35.0	)		(38.7	)		(47.3	)
	Increase in liability (warranty issued during period)		26.8			28.4			25.5
	Net adjustments to liability		0.7			(9.6	)		15.3
	Accretion (for Predecessor liabilities)		0.6			0.7			0.8
	Ending balance	$	83.6		$	90.5		$	109.7

DEFERRED_REVENUE_Tables

DEFERRED REVENUE (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Revenue for Extended Transmission Coverage Activity	Deferred revenue for ETC activity (dollars in millions):
		Year ended			Year ended			Year ended
		December 31,			December 31,			December 31,
		2014			2013			2012
	Beginning balance	$	63.6		$	63.5		$	60.5
	Increases		26.2			21.1			22.9
	Revenue earned		(20.8	)		(21.0	)		(19.9	)
	Ending balance	$	69		$	63.6		$	63.5

OTHER_EXPENSE_NET_Tables

OTHER EXPENSE, NET (Tables)	12 Months Ended
	Dec. 31, 2014
Computation of Other Expense, Net	Other expense, net consists of the following (dollars in millions):
		Years ended December 31,
		2014			2013			2012
	Loss on intercompany foreign exchange	$	(5.4	)	$	(2.3	)	$	—
	Grant program income		2.6			5.2			11.5
	Impairment loss on investments in technology-related initiatives		(2.0	)		(5.0	)		(14.4	)
	Gain on negotiation of commercial agreement		2			—			—
	Public offering fees and expenses		(1.4	)		(1.6	)		(6.1	)
	Unrealized gain (loss) on derivative contracts (see NOTE 8)		1.2			(1.5	)		0.9
	Realized loss on derivative contracts (see NOTE 8)		(1.0	)		(2.8	)		(1.3	)
	Loss on foreign exchange		(1.0	)		(2.4	)		(2.6	)
	Loss on repayments and repurchases of long-term debt (see NOTE 7)		(0.5	)		(0.8	)		(22.1	)
	Termination of services agreement		—			—			(16.0	)
	Loss on re-measurement of employee benefit plans (see NOTE 13)		—			—			(2.3	)
	Other		(0.1	)		0.3			(0.4	)
	Total	$	(5.6	)	$	(10.9	)	$	(52.8	)

OTHER_CURRENT_LIABILITIES_Tabl

OTHER CURRENT LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Other Current Liabilities	Other current liabilities consist of the following (dollars in millions):
		As of		As of
		December 31,		December 31,
		2014		2013
	Payroll and related costs	$	50.9	$	32.7
	Sales allowances		25.5		26.9
	Defense price reduction reserve		16.2		26.8
	Vendor buyback obligation		13.2		11.8
	Taxes payable		8.5		8.6
	Accrued interest payable		5.2		11.2
	Derivative liabilities		0.8		20.2
	Other accruals		11.4		14.1
	Total	$	131.7	$	152.3

EMPLOYEE_BENEFIT_PLANS_Tables

EMPLOYEE BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2014
Net Periodic Benefit Costs	Information about the net periodic benefit cost and other changes recognized in AOCL for the pension and post-retirement benefit plans is as follows (dollars in millions):
			Pension Plans									Post-retirement Benefits
			Year ended			Year ended			Year ended			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,			December 31,			December 31,			December 31,
			2014			2013			2012			2014			2013			2012
	Net Periodic Benefit Cost:
	Service cost		$	13.2		$	16.3		$	15.2		$	2.2		$	3.3		$	3.9
	Interest cost			5			4			4.1			5.9			5.8			7.2
	Expected return on assets			(7.7	)		(6.7	)		(5.9	)		—			—			—
	Prior service cost			0.1			0.1			0.1			(3.6	)		(3.6	)		—
	Loss (gain)			—			0.7			1.2			(0.7	)		—			—
	Settlement loss			—			—			2.3			—			—			—
	Net Periodic Benefit Cost		$	10.6		$	14.4		$	17		$	3.8		$	5.5		$	11.1
	Other changes recognized in other comprehensive income:
	Prior service credit		$	—		$	—		$	—		$	—		$	—		$	(28.9	)
	Net loss (gain)			2.1			(18.4	)		(2.1	)		7.8			(30.7	)		3.8
	Amortizations			(0.1	)		(0.8	)		(3.6	)		4.3			3.6			—
	Total recognized – other comprehensive income		$	2		$	(19.2	)	$	(5.7	)	$	12.1		$	(27.1	)	$	(25.1	)
Health Care Costs Trends	As health care costs trends have a significant effect on the amounts reported, an increase and decrease of one-percentage-point would have the following effects in the year ended December 31, 2014 (dollars in millions):
			1% Increase			1% Decrease
	Effect on total of service and interest cost		$	1.7		$	(1.3	)
	Effect on post-retirement benefit obligation		$	28.6		$	(22.3	)
Reconciliation of Changes in Net Benefit Obligations and Fair Value of Plan Assets	The following table provides a reconciliation of the changes in the net benefit obligations and fair value of plan assets for the years ended December 31, 2014, 2013 and 2012 (dollars in millions):
			Pension Plans									Post-retirement Benefits
			Year ended			Year ended			Year ended			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,			December 31,			December 31,			December 31,
			2014			2013			2012			2014			2013			2012
	Benefit Obligations:
	Net benefit obligation at beginning of year		$	105.9		$	103.3		$	99.7		$	120.7		$	142.6		$	156.6
	Service cost			13.2			16.3			15.2			2.2			3.3			3.9
	Interest cost			5			4			4.1			5.9			5.8			7.2
	Plan Amendments			—			—			—			—			—			(28.9	)
	Settlements			—			—			(18.8	)		—			—			—
	Benefits paid			(1.5	)		(0.8	)		(0.4	)		(0.6	)		(0.3	)		—
	Actuarial loss (gain)			10.9			(16.9	)		3.5			7.8			(30.7	)		3.8
	Net benefit obligation at end of year		$	133.5		$	105.9		$	103.3		$	136		$	120.7		$	142.6
	Fair Value of Plan Assets:
	Fair value of plan assets at beginning of year		$	108.6		$	89.4		$	83.4		$	—		$	—		$	—
	Actual return on plan assets			16.4			8.2			11.5			—			—			—
	Employer contributions			11.8			11.8			13.7			0.6			0.3			—
	Settlements			—			—			(18.8	)		—			—			—
	Benefits paid			(1.5	)		(0.8	)		(0.4	)		(0.6	)		(0.3	)		—
	Fair value of plan assets at end of year		$	135.3		$	108.6		$	89.4		$	—		$	—		$	—
	Net Funded Status		$	1.8		$	2.7		$	(13.9	)	$	(136.0	)	$	(120.7	)	$	(142.6	)
Fair Value of Plan Assets	The fair values of plan assets for the Company’s pension plans as of December 31, 2014 and 2013 are as follows (dollars in millions):
			Quoted Prices in Active Markets
			for Identical Assets (Level 1)
			2014						2013
	Asset Category		Fair Value			%			Fair Value			%
	Cash and cash equivalents		$	8.6			6	%	$	3.6			3	%
	Diversified equity securities			57.8			43			51.5			48
	Diversified debt securities			68.9			51			53.5			49
	Total		$	135.3			100	%	$	108.6			100	%
Schedule of Allocation of Plan Assets	To achieve these objectives the Company has established the following targets:
			Target
	Asset Category		Hourly			Salary
	Cash and cash equivalents			5	%		8	%
	Diversified equity securities			39			46
	Diversified debt securities			56			46
	Total			100	%		100	%
Amounts Recognized in Balance Sheet and in Accumulated Other Comprehensive Income AOCI	The following table discloses the amounts recognized in the balance sheet and in AOCL at December 31, 2014 and 2013, on a pre-tax basis (dollars in millions):
			Pension Plans						Post-retirement Benefits
			As of December 31,
			2014			2013			2014			2013
	Amounts Recognized in Balance Sheet:
	Noncurrent assets		$	7.9		$	7.4		$	—		$	—
	Current liabilities			—			—			(1.2	)		(1.4	)
	Noncurrent liabilities			(6.1	)		(4.7	)		(134.8	)		(119.3	)
	Total asset (liability)		$	1.8		$	2.7		$	(136.0	)	$	(120.7	)
	Accumulated Other Comprehensive Loss:
	Prior service (cost) credit		$	(0.1	)	$	(0.2	)	$	21.7		$	25.4
	Actuarial gain			0.6			2.7			8.6			17.1
	Total		$	0.5		$	2.5		$	30.3		$	42.5
Amounts in Accumulated Other Comprehensive Income AOCI Expected to be Amortized and Recognized as Component of Net Periodic Benefit Cost in Two Thousand Thirteen	The amounts in AOCL expected to be amortized and recognized as a component of net periodic benefit cost in 2015 are as follows (dollars in millions):
			2015
			Pension			Post-retirement
			Plans			Benefits
	Prior service (cost) credit		$	(1.0	)	$	3.6
	Actuarial loss			1			—
	Total		$	0		$	3.6
Projected and Accumulated Benefit Obligation and Fair Value of Plan Assets for Pension Plans with Projected Benefit Obligation in Excess of Plan Assets	As of December 31, 2014 and 2013, the projected benefit obligation, the accumulated benefit obligation, and the fair value of plan assets for pension plans with a projected benefit obligation in excess of plan assets and for pension plans with an accumulated benefit obligation in excess of plan assets were as follows (dollars in millions):
			Hourly Plan						Salary Plan
			As of December 31,
			2014			2013			2014			2013
	Plans with projected benefit obligation in excess of plan assets:
	Projected benefit obligation			N/A	1		N/A	1	$	71.4		$	53.8
	Fair value of plan assets			N/A	1		N/A	1	$	65.3		$	49.1
	Plans with accumulated benefit obligation in excess of plan assets:
	Accumulated benefit obligation			N/A	1		N/A	1	$	67.6		$	50.9
	Fair value of plan assets			N/A	1		N/A	1	$	65.3		$	49.1
	1	As of December 31, 2014 and 2013, the hourly defined benefit pension plan had plan assets greater than both the projected benefit obligation and accumulated benefit obligation.
Expected Cash Flows for Pension and Post-Retirement Benefit Plans	Information about expected cash flows for the Company’s pension and post-retirement benefit plans is as follows (dollars in millions):
			Pension			Post-retirement
			Plans			Benefits
	Employer Contributions:
	2015 expected contributions		$	2		$	1.2
	Expected Benefit Payments:
	2015			2.3			1.2
	2016			3			1.7
	2017			3.8			2.4
	2018			4.6			3.2
	2019			5.5			3.9
	2020-2024			40.6			27.7
Benefit Obligation
Weighted-Average Actuarial Assumptions	The table below provides the weighted-average actuarial assumptions used to determine the benefit obligations of the Company’s plans.
			Pension Plans						Post-retirement Benefits
			As of December 31,
			2014			2013			2014			2013
	Discount rate			3.9	%		4.8	%		4	%		4.9	%
	Rate of compensation increase (salaried)			3	%		3	%		N/A			N/A
Benefit Costs
Weighted-Average Actuarial Assumptions	The table below provides the weighted-average actuarial assumptions used to determine the net periodic benefit cost.
			Pension Plans									Post-retirement Benefits
			Year ended			Year ended			Year ended			Year ended			Year ended			Year ended
			December 31,			December 31,			December 31,			December 31,			December 31,			December 31,
			2014			2013			2012			2014			2013			2012
	Discount rate			4.8	%		3.9	%		4.6	%		4.9	%		4.1	%		4.6	%
	Rate of compensation increase (salaried)			3	%		3	%		4	%		N/A			N/A			N/A
	Expected return on assets			6.8	%		7	%		7	%		N/A			N/A			N/A

STOCKBASED_COMPENSATION_Tables

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2014
Assumptions Used to Calculate Fair Value of Option Award	When options are granted, the Company uses a Black-Scholes option pricing model to calculate the fair value of each option award using the assumptions noted in the following table:
		2014			2013			2012
	Expected volatility		38	%		51	%		N/A
	Expected dividend yield		1.6	%		1.2	%		N/A
	Expected term (in years)		5.5			5.4			N/A
	Expected forfeitures		0	%		0	%		N/A
	Risk-free rate		1.7	%		1.6	%		N/A
Option Activity	A summary of option activity as of December 31, 2014, 2013 and 2012, and changes during the period then ended is presented below:
		Options			Weighted-			Weighted-Average
		(in millions)			Average Exercise			Remaining
					Price			Contractual Term
	Outstanding as of December 31, 2011		14.9		$	13.4			4.94 years
	Exercisable as of December 31, 2011		11.5		$	13.37			4.88 years
	Granted		—			—
	Exercised		(2.7	)		—
	Forfeited or expired		(0.3	)		—
	Outstanding as of December 31, 2012		11.9		$	14.01			4.93 years
	Exercisable as of December 31, 2012		11.8		$	14.02			4.91 years
	Granted		0.6		$	23.39
	Exercised		(3.8	)		—
	Forfeited or expired		—			—
	Outstanding as of December 31, 2013		8.7		$	15.33			4.30 years
	Exercisable as of December 31, 2013		8.1		$	14.79			3.94 years
	Granted		0.4		$	30.23
	Exercised		(4.2	)		—
	Forfeited or expired		—			—
	Outstanding as of December 31, 2014		4.9		$	17.49			4.19 years
	Exercisable as of December 31, 2014		3.9		$	15.32			3.08 years
Restricted Stock Units (RSUs)
Non-Vested Shares Activity	A summary of RSU activity as of December 31, 2014, 2013 and 2012, and changes during the period then ended is presented below:
	Non-vested RSUs:	RSUs			Weighted-Average
		(in millions)			Grant-Date
					Fair Value
	Non-vested as of December 31, 2011		—		$	—
	Granted		1			20.2
	Vested		—			—
	Forfeited		—			—
	Non-vested as of December 31, 2012		1		$	20.2
	Granted		0.2			23.31
	Vested		(0.4	)		20.23
	Forfeited		—			—
	Non-vested as of December 31, 2013		0.8		$	20.9
	Granted		0			29.85
	Vested		(0.6	)		20.32
	Forfeited		—			—
	Non-vested as of December 31, 2014		0.2		$	26.57
Employee Stock Option
Non-Vested Shares Activity	A summary of the status of the Company’s non-vested stock options as of December 31, 2014, 2013 and 2012, and changes during the period ended December 31, 2014, 2013 and 2012 is presented below:
	Non-vested Stock Options:	Options			Weighted-Average
		(in millions)			Grant-Date
					Fair Value
	Non-vested at December 31, 2011		3.4		$	2.81
	Granted		—			—
	Vested		(2.9	)		2.58
	Forfeited		(0.3	)		4
	Non-vested at December 31, 2012		0.2		$	4.34
	Granted		0.6			9.76
	Vested		(0.2	)		3.59
	Forfeited		—			—
	Non-vested at December 31, 2013		0.6		$	9.06
	Granted		0.4			9.51
	Vested		—			—
	Forfeited		—			—
	Non-vested at December 31, 2014		1		$	9.44
Restricted Stock
Non-Vested Shares Activity	A summary of restricted stock activity as of December 31, 2014 and changes during the period then ended is presented below:
	Non-vested Shares:	Restricted			Weighted-Average
		Stock			Grant-Date Fair
		(in millions)			Value
	Non-vested as of December 31, 2013		—		$	—
	Granted		0.2			29.47
	Vested		—			—
	Forfeited		—			—
	Non-vested as of December 31, 2014		0.2		$	29.47

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2014
Income Loss Before Income Taxes	Income before income taxes included the following (dollars in millions):
		Years ended December 31,
		2014			2013			2012
	U.S. income	$	355.1		$	259		$	204.1
	Foreign income		13			7.1			12.1
	Total	$	368.1		$	266.1		$	216.2
Provision for Income Tax Expense	The provision for income tax expense (benefit) was estimated as follows (dollars in millions):
		Years ended December 31,
		2014			2013			2012
	Estimated current income taxes:
	U.S. federal	$	1.6		$	0.2		$	1.5
	Foreign		6.3			1.9			3.9
	U.S. state and local		(0.2	)		0.6			0.4
	Total Current		7.7			2.7			5.8
	Deferred income tax expense (credit), net:
	U.S. federal		125.6			87.6			(282.5	)
	Foreign		(0.3	)		0.1			0.1
	U.S. state and local		6.5			10.3			(21.4	)
	Total Deferred		131.8			98			(303.8	)
	Total income tax expense (benefit)	$	139.5		$	100.7		$	(298.0	)
Reconciliation of Provision for Income Tax Expense (Benefit)	A reconciliation of the provision for income tax expense (benefit) compared with the amounts at the U.S. federal statutory rate is as follows (dollars in millions):
		Years ended December 31,
		2014			2013			2012
	Tax at U.S. statutory income tax rate	$	128.9		$	93.1		$	75.7
	Foreign rate differential		(2.3	)		(0.7	)		(2.6	)
	Non-deductible expenses		3.9			0.8			4.2
	Valuation allowance		2.6			1			(384.1	)
	State tax expense		4			7.3			5.7
	Adjustment to deferred tax expense		2.4			(0.3	)		2.2
	Other adjustments		(0.0	)		(0.5	)		0.9
	Total income tax expense (benefit)	$	139.5		$	100.7		$	(298.0	)
Deferred Tax Assets and Liabilities	Temporary differences and carryforwards that gave rise to deferred tax assets and liabilities included the following (dollars in millions):
		As of			As of
		December 31,			December 31,
		2014			2013
	Deferred tax assets:
	Inventories	$	5.1		$	4.6
	Warranty accrual		30.5			32.7
	Sales allowances and rebates		6.7			7.9
	Deferred revenue		25.7			24
	Post-retirement health care		5.7			—
	Intangibles		77.3			83.6
	Other accrued liabilities		32.7			27.2
	Unrealized loss on interest rate derivatives		5.7			3.7
	Operating loss carryforwards		107.8			140.7
	Stock based compensation		6.9			12.5
	Technology-related investments		6.6			6.8
	Loan fees		—			0.9
	Other		16.4			10.4
	Total Deferred tax assets		327.1			355
	Valuation allowances		(5.2	)		(2.8	)
	Deferred tax liabilities:
	Property, plant and equipment		(20.2	)		(22.0	)
	Goodwill		(320.8	)		(280.3	)
	Trade name		(90.3	)		(60.6	)
	Product warranty liabilities		(4.3	)		(5.6	)
	Pension		—			(0.5	)
	Post-retirement health care		—			(0.2	)
	Other		(3.5	)		—
	Total Deferred tax liabilities		(439.1	)		(369.2	)
	Net Deferred tax liability	$	(117.2	)	$	(17.0	)
Liability for Unrecognized Tax Benefit	The change in the liability for unrecognized tax benefits are as follows (dollars in millions):
	December 31, 2012	$	—
	December 31, 2013	$	2.3
	Increases in unrecognized tax benefits as a result of current year activity		0.2
	December 31, 2014	$	2.5

OTHER_COMPREHENSIVE_LOSS_Table

OTHER COMPREHENSIVE LOSS (Tables)	12 Months Ended
	Dec. 31, 2014
Changes in Components of Accumulated Other Comprehensive Loss	The changes in components of accumulated other comprehensive loss consisted of the following (dollars in millions):
		Before Tax			Tax (Expense)			After Tax
					Benefit
	Balance at December 31, 2011	$	(33.2	)	$	(23.8	)	$	(57.0	)
	Foreign currency translation		(0.7	)		—			(0.7	)
	Pension and OPEB liability adjustment		26.7			(11.6	)		15.1
	Available-for-sale securities		(2.0	)		0.7			(1.3	)
	Net current period other comprehensive loss	$	24		$	(10.9	)	$	13.1
	Balance at December 31, 2012	$	(9.2	)	$	(34.7	)	$	(43.9	)
	Foreign currency translation		(5.0	)		—			(5.0	)
	Pension and OPEB liability adjustment		46.4			(17.4	)		29
	Available-for-sale securities		(1.9	)		0.8			(1.1	)
	Net current period other comprehensive income	$	39.5		$	(16.6	)	$	22.9
	Balance at December 31, 2013	$	30.3		$	(51.3	)	$	(21.0	)
	Foreign currency translation		(7.4	)		—			(7.4	)
	Pension and OPEB liability adjustment		(14.6	)		5.5			(9.1	)
	Available-for-sale securities		(3.2	)		1.2			(2.0	)
	Net current period other comprehensive loss	$	(25.2	)	$	6.7		$	(18.5	)
	Balance at December 31, 2014	$	5.1		$	(44.6	)	$	(39.5	)
Consolidated Statements of Comprehensive Income Affected by Reclassifications from by AOCL	The following table shows the location in the Consolidated Statements of Comprehensive Income affected by reclassifications from AOCL (dollars in millions):
		For the year ended December 31, 2014
	AOCL Components	Amount			Affected line item in the consolidated
		reclassified from			statements of comprehensive income
		AOCL
	Amortization of defined benefit pension items:
	Prior service cost	$	3.2		Cost of sales
			0.3		Selling, general and
					administrative
			0.1		Engineering – research and
					development
	Actuarial loss		0.7		Cost of sales
			(0.0	)	Selling, general and
					administrative
			(0.0	)	Engineering – research and
					development
	Total reclassifications, before tax		4.3		Income before income
					taxes
	Income tax expense		(1.6	)	Tax expense
	Total reclassifications	$	2.7		Net of tax

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2014
Future Payments under Non-Cancelable Operating Leases	As of December 31, 2014, future payments under non-cancelable operating leases are as follows over each of the next five years and thereafter (dollars in millions):
	2015	$	4.6
	2016		2.8
	2017		1.7
	2018		0.8
	2019		0.6
	Thereafter		2
	Total	$	12.5

CONCENTRATION_OF_RISK_Tables

CONCENTRATION OF RISK (Tables)	12 Months Ended
	Dec. 31, 2014
Schedules of Concentration of Risk by Risk Factor	Three customers accounted for greater than 10% of net sales within the last three years presented.
		Years ended December 31,
	% of net sales	2014			2013			2012
	Daimler AG		17	%		17	%		13	%
	Navistar, Inc.		10	%		10	%		11	%
	Oshkosh Corporation		4	%		8	%		11	%
	No other customers accounted for more than 10% of net sales of the Company during the years ended December 31, 2014, 2013 or 2012.
	Three customers accounted for greater than 10% of outstanding accounts receivable within the last two years presented.
	% of accounts receivable	As of			As of
		December 31,			December 31,
		2014			2013
	Daimler AG		15	%		15	%
	Navistar, Inc.		12	%		10	%
	AB Volvo.		8	%		11	%
	No other customers accounted for more than 10% of the outstanding accounts receivable as of December 31, 2014 or December 31, 2013.
	One supplier accounted for greater than 10% of materials purchased for the periods presented:
		Years ended December 31,
	% of material purchased	2014			2013			2012
	Linamar Corporation Inc.		10	%		13	%		13	%

EARNINGS_PER_SHARE_Tables

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2014
Reconciliation of Numerators and Denominators Used to Calculate Basic EPS and Diluted EPS	The following table reconciles the numerators and denominators used to calculate basic EPS and diluted EPS (in millions, except per share data):
		Years ended December 31,
		2014		2013		2012
	Net income	$	228.6	$	165.4	$	514.2
	Weighted average shares of common stock outstanding		179.8		184.5		182
	Dilutive effect stock-based awards		2.5		3.4		4.2
	Diluted weighted average shares of common stock outstanding		182.3		187.9		186.2
	Basic earnings per share attributable to common stockholders	$	1.27	$	0.9	$	2.83
	Diluted earnings per share attributable to common stockholders	$	1.25	$	0.88	$	2.76

GEOGRAPHIC_INFORMATION_Tables

GEOGRAPHIC INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2014
Net Sales by Country	The Company had the following net sales by country as follows (dollars in millions):
		Years ended December 31,
		2014		2013		2012
	United States	$	1,578.00	$	1,354.30	$	1,509.60
	China		128.7		141		136.4
	Canada		85.1		88.6		123
	Japan		45.8		37		52
	Germany		38.1		53.9		39.1
	United Kingdom		36.8		42.5		74.1
	Other		214.9		209.5		207.6
	Total	$	2,127.40	$	1,926.80	$	2,141.80
Schedule of Disclosure of Long-Lived Assets by Geographic Location	The Company had net long-lived assets by country as follows (dollars in millions):
		Years ended December 31,
		2014		2013		2012
	United States	$	442.6	$	478.7	$	493.6
	India		51.5		59.9		76.8
	Hungary		15.1		18.1		18.4
	Others		5.4		6.7		7.4
	Total	$	514.6	$	563.4	$	596.2

QUARTERLY_FINANCIAL_INFORMATIO1

QUARTERLY FINANCIAL INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Data	The following is a summary of the unaudited quarterly results of operations. The Company believes that all adjustments considered necessary for a fair presentation in accordance with GAAP have been included (unaudited, in millions, except per share data).
		Quarters ended,
		March 31		June 30		September 30		December 31
	2014
	Net sales	$	493.6	$	536.1	$	553.3	$	544.4
	Gross profit		222.5		238.5		259.3		255.6
	Operating income		114.8		132.2		147.3		117.8
	Income before income taxes		79.3		94.7		116.3		77.8
	Net income		52.1		57.2		68.8		50.5
	Basic earnings per share	$	0.29	$	0.32	$	0.38	$	0.28
	Diluted earnings per share	$	0.28	$	0.31	$	0.38	$	0.28
	2013
	Net sales	$	457.4	$	512.1	$	466.3	$	491
	Gross profit		198.3		226.1		206.1		211.4
	Operating income		81.4		117.7		111.2		99.6
	Income before income taxes		44.4		81.8		72.4		67.5
	Net income		27.5		50.5		44.5		42.9
	Basic earnings per share	$	0.15	$	0.27	$	0.24	$	0.24
	Diluted earnings per share	$	0.15	$	0.26	$	0.24	$	0.23

Overview_Additional_Informatio

Overview - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Product
	Customer
	Employee
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Transmission product lines	13
Worldwide independent distributor and dealer locations	1,400
Number of employees	2,700
Revenues | North America
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Concentration of risk, percentage	80.00%

Recovered_Sheet1

Summary of Significant Accounting Polices - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Segment
Summary Of Significant Accounting Policies [Line Items]
Number of operating segment	1
Number of reportable segment	1
Highly-liquid investments with original maturities	90 days
Loss associated with impairment of long-lived assets	$15.40
Accrued expenses related to impaired long-lived assets	1.7
Amortization of deferred financing costs	8.1	10.9	14.5
Sales incentives	66.9	65.2	59.9
Military price reduction reserve	63.1	49.6
Deferred revenue recognized	8.8
Engineering services revenue	7.4	12.4	7.8
Increase in defined benefit obligation due to one percentage point decrease in assumed discount rate	22.3
Pension Plans
Summary Of Significant Accounting Policies [Line Items]
Increase in defined benefit obligation due to one percentage point decrease in assumed discount rate	20
Post-retirement Benefits
Summary Of Significant Accounting Policies [Line Items]
Increase in defined benefit obligation due to one percentage point decrease in assumed discount rate	$23.70
Minimum
Summary Of Significant Accounting Policies [Line Items]
Extended Transmission Coverage sales, recognition period	2 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Extended Transmission Coverage sales, recognition period	5 years

Property_Plant_and_Equipment_E

Property Plant and Equipment Estimated Lives (Detail)	12 Months Ended
	Dec. 31, 2014
Minimum | Land Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	5 years
Minimum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	10 years
Minimum | Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	2 years
Minimum | Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	2 years
Minimum | Special tools
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	2 years
Maximum | Land Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	30 years
Maximum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	40 years
Maximum | Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	20 years
Maximum | Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	5 years
Maximum | Special tools
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated Lives	10 years

Components_of_Inventories_Deta

Components of Inventories (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventory [Line Items]
Purchased parts and raw materials	$72.30	$79.70
Work in progress	6.1	5.7
Service parts	46.5	45.8
Finished goods	18.6	29.2
Total inventories	$143.50	$160.40

Cost_and_Accumulated_Depreciat

Cost and Accumulated Depreciation of Property Plant and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Property, Plant and Equipment [Line Items]
Land and land improvements	$23.60	$20.30
Buildings and building improvements	281.6	271.4
Machinery and equipment	576.2	567.7
Software	117	112.9
Special tools	143.6	143.4
Construction in progress	39.9	48.6
Total property, plant and equipment	1,181.90	1,164.30
Accumulated depreciation	-667.3	-600.9
Property, plant and equipment, net	$514.60	$563.40	$596.20

Property_Plant_and_Equipment_A

Property Plant and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Depreciation of property, plant and equipment	$93.80	$98.70	$102.50

Recovered_Sheet2

Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Line Items]
Goodwill	$1,941	$1,941
Amortization of intangible assets	98.8	105.3	150
Net carrying value of Goodwill and other intangible assets	$3,453

Summary_of_Goodwill_and_Other_

Summary of Goodwill and Other Intangible Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Line Items]
Trade name	$870	$870
Intangible assets, gross	2,551	2,551
Accumulated amortization	-1,039	-940.2
Intangible assets, net	1,512	1,610.80
Customer relationships - defense
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, gross	62.3	62.3
Accumulated amortization	-27.9	-24.4
Intangible assets, net	34.4	37.9
Customer relationships - commercial
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, gross	831.8	831.8
Accumulated amortization	-426.9	-374.9
Intangible assets, net	404.9	456.9
Proprietary technology
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, gross	476.3	476.3
Accumulated amortization	-282	-243.9
Intangible assets, net	194.3	232.4
Non-compete agreement
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, gross	17.3	17.3
Accumulated amortization	-12.8	-11.1
Intangible assets, net	4.5	6.2
Patented technology - defense
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, gross	28.2	28.2
Accumulated amortization	-24.5	-21.2
Intangible assets, net	3.7	7
Tooling rights
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, gross	4.5	4.5
Accumulated amortization	-4.3	-4.1
Intangible assets, net	0.2	0.4
Patented technology - commercial
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, gross	260.6	260.6
Accumulated amortization	($260.60)	($260.60)

Expected_Amortization_Expense_

Expected Amortization Expense Related to Other Intangible Assets (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Finite-Lived Intangible Assets
2015	$97.10
2016	92.4
2017	89.7
2018	87.2
2019	85.7
Thereafter	$189.90

Fair_Value_of_Financial_Assets

Fair Value of Financial Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$55	$5
Available-for-sale securities	8.6	8.2
Rabbi trust assets	2.9	1.3
Deferred compensation obligation	-2.9	-1.3
Derivative assets	0	1.6
Derivative liabilities	-15.4	-21.4
Total	48.2	-6.6
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	55	5
Available-for-sale securities	8.6	8.2
Rabbi trust assets	2.9	1.3
Deferred compensation obligation	-2.9	-1.3
Total	63.6	13.2
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	1.6
Derivative liabilities	-15.4	-21.4
Total	($15.40)	($19.80)

Long_Term_Debt_and_Maturities_

Long Term Debt and Maturities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Instrument [Line Items]
Total long-term debt	$2,520.50	$2,678.30
Less: current maturities of long-term debt	17.9	17.9
Total long-term debt less current portion	2,502.60	2,660.40
Total long-term debt	2,520.50	2,678.30
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017
Debt Instrument [Line Items]
Total long-term debt	283.6	423.5
Total long-term debt	283.6	423.5
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019
Debt Instrument [Line Items]
Total long-term debt	1,765.60	1,783.50
Total long-term debt	1,765.60	1,783.50
Senior Notes, fixed 7.125%, due 2019
Debt Instrument [Line Items]
Total long-term debt	471.3	471.3
Total long-term debt	$471.30	$471.30

Long_Term_Debt_and_Maturities_1

Long Term Debt and Maturities (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017
Debt Instrument [Line Items]
Debt instrument, due date	2017
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019
Debt Instrument [Line Items]
Debt instrument, due date	2019
Senior Notes, fixed 7.125%, due 2019
Debt Instrument [Line Items]
Interest rate of Senior Notes	7.13%
Debt instrument, due date	2019

Principal_Payments_Required_on

Principal Payments Required on Long Term Debt (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Long Term Debt [Line Items]
2015	$17.90
2016	17.9
2017	301.4
2018	17.9
2019	$2,165.40

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2012	Dec. 31, 2007	Feb. 28, 2013	Dec. 31, 2013	Aug. 30, 2013	Oct. 31, 2012	Apr. 30, 2014
Debt Instrument [Line Items]
Total long-term debt	$2,520.50	$2,678.30					$2,678.30
Fair value of long-term debt obligations	2,515.90
Additional deferred financing fees recorded	0.9	14.9	20.2
Deferred financing fees	8.1	10.9	14.5
Long-term debt repayment	157.6	142.4	245.4
Losses associated with deferred debt issuance costs on principal payments	0.5	0.8	22.1
Total leverage ratio	305.00%
Maximum
Debt Instrument [Line Items]
Annual excess cash flow to prepay term loan	50.00%
Line of Credit
Debt Instrument [Line Items]
Extended Senior Secured Credit Facility, principal amount	801.1
Applicable margin over base rate	3.50%
Additional deferred financing fees recorded				16.1
Debt instrument face amount				850
Weighted average rate on the Senior Secured Credit Facility	3.64%
Line of Credit | Amendment Agreement
Debt Instrument [Line Items]
Deferred financing fees				4.5
Line of Credit | Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate				0.50%	0.50%
Line of Credit | Variable Interest Rate Option One | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate				3.00%
Line of Credit | Variable Interest Rate Option One | Prime Rate or Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate				2.00%
Line of Credit | Variable Interest Rate Option Two | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate				3.25%
Line of Credit | Variable Interest Rate Option Two | Prime Rate or Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate				2.25%
Line of Credit | Minimum
Debt Instrument [Line Items]
Extended period of amortization on deferred financing fees	2014
Line of Credit | Maximum
Debt Instrument [Line Items]
Extended period of amortization on deferred financing fees	2017
Senior Secured Credit Facility
Debt Instrument [Line Items]
Additional deferred financing fees recorded						1.6
Deferred financing fees						1
Revolving Credit Facility
Debt Instrument [Line Items]
Additional deferred financing fees recorded							2.1
Deferred financing fees	0.6						0.4
Revolving credit borrowings	465	410					410
Maturity date of revolving credit borrowings	2019-01						2019-01
Line of Credit Facility, commitment fee percentage	0.25%
Maximum amount of letters of credit commitments available under the revolving credit facility	75	75					75
Maximum amount outstanding at any time on the revolving credit facility	40
Available revolving credit facility	455.1
Letters of Credit	9.9
Revolving credit borrowings, interest rate	1.92%
Required senior secured leverage ratio	550.00%
Achieved senior secured leverage ratio	242.00%
Minimum senior secured leverage ratio	350.00%
Basis point reduction to applicable margin, resulting from total leverage ratio below minimum	0.25%
Basis point reduction to commitment fee, resulting from total leverage ratio below minimum	0.13%
Revolving Credit Facility | Variable Interest Rate Option One | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate							2.25%
Revolving Credit Facility | Variable Interest Rate Option One | Base Rate
Debt Instrument [Line Items]
Applicable margin over base rate							1.25%
Revolving Credit Facility | Variable Interest Rate Option Two | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate							2.00%
Revolving Credit Facility | Variable Interest Rate Option Two | Base Rate
Debt Instrument [Line Items]
Applicable margin over base rate							1.00%
Revolving Credit Facility | Variable Interest Rate Option Three | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate							1.75%
Revolving Credit Facility | Variable Interest Rate Option Three | Base Rate
Debt Instrument [Line Items]
Applicable margin over base rate							0.75%
Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Line of Credit Facility, commitment fee percentage							0.25%
Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Line of Credit Facility, commitment fee percentage							0.38%
Senior Secured Credit Facility Term B-2 Loan, due 2017
Debt Instrument [Line Items]
Additional deferred financing fees recorded	2.3
Deferred financing fees for which the amortization period was extended as a result of debt modification	5.1
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019
Debt Instrument [Line Items]
Total long-term debt	1,765.60	1,783.50					1,783.50
Additional deferred financing fees recorded							10.1	1	1.8
Debt instrument face amount		650					650
Senior Secured Credit Facility, extended maturity date			2019-08						2019-08
Variable interest rate, description	In August 2012, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $850.0 million of term loan debt from August 2014 to August 2019 and to increase the applicable margin at the Company's option to either (a) 3.25% or 3.00%, subject to the Company's total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 2.25% or 2.00%, subject to the Company's total leverage ratio,
Deferred financing fees							0.5	2.1	1.4
Total interest rate for term loan	3.75%
Principal payments on term loans	4.5
Debt instrument, due date	2019
Basis point reduction to applicable margin, resulting from total leverage ratio below minimum	0.25%
Total leverage ratio	325.00%
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019 | LIBOR
Debt Instrument [Line Items]
Credit facility refinanced amount								1,139.30
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019 | Prime Rate or Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate							0.50%	0.50%	0.50%
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019 | Variable Interest Rate Option One | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate							2.75%	2.75%	3.25%
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019 | Variable Interest Rate Option One | Prime Rate or Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate							1.75%	1.75%	2.25%
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019 | Variable Interest Rate Option Two | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate							2.50%	2.50%	3.00%
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019 | Variable Interest Rate Option Two | Prime Rate or Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate							1.50%	1.50%	2.00%
Senior Secured Credit Facility Term B-3 Loan, variable, due 2019 | Line of Credit
Debt Instrument [Line Items]
Senior Secured Credit Facility, extended maturity date							2019-08
Variable interest rate, description	In October 2012, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $300.0 million of term loan debt from August 2014 to August 2019 and to increase the applicable margin at the Company's option to either (a) 3.25% or 3.00%, subject to the Company's total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 2.25% or 2.00%, subject to the Company's total leverage ratio,
Credit facility refinance description	In August 2013, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to refinance $1,139.3 million of term loan debt and decrease the applicable margin for such term loans at the Company's option to either (a) 2.75% or 2.50%, subject to the Company's total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 1.75% or 1.50%, subject to the Company's total leverage ratio, over the greater of the prime lending						In December 2013, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $650.0 million of term loan debt from August 2017 to August 2019 and to reduce the applicable margin at the Company's option to either (a) 2.75% or 2.50%, subject to the Company's total leverage ratio, over the LIBOR (which may not be less than 1.00%) or (b) 1.75% or 1.50%, subject to the Company's total leverage ratio
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017
Debt Instrument [Line Items]
Total long-term debt	283.6	423.5					423.5
Variable interest rate, description	In February 2013, ATI also entered into an additional amendment with the term loan lenders under its Senior Secured Credit Facility to extend the maturity of $411.4 million of term loan debt from August 2014 to August 2017 and to increase the applicable margin at the Company's option to either (a) 3.00% over the LIBOR or (b) 2.00% over the greater of the prime lending rate
Deferred financing fees										0.3
Credit facility refinance description	In February 2013, ATI entered into an amendment with the term loan lenders under its Senior Secured Credit Facility to refinance $793.1 million of term loan debt and decrease the applicable margin for such term loans at the Company's option to either (a) 3.00% over the LIBOR or (b) 2.00% over the greater of the prime lending rate
Total interest rate for term loan	2.92%
Debt instrument, due date	2017
Long-term debt repayment	140
Losses associated with deferred debt issuance costs on principal payments	0.5
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Amendment
Debt Instrument [Line Items]
Senior Secured Credit Facility Term loan, due date						2017-08
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate										0.50%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate										2.75%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | LIBOR | Refinanced Term Loan
Debt Instrument [Line Items]
Applicable margin over base rate						3.00%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | LIBOR | Amendment
Debt Instrument [Line Items]
Applicable margin over base rate						3.00%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Prime Rate or Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate										1.75%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Prime Rate or Federal Funds Rate | Refinanced Term Loan
Debt Instrument [Line Items]
Applicable margin over base rate						0.50%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Prime Rate or Federal Funds Rate | Amendment
Debt Instrument [Line Items]
Applicable margin over base rate						2.00%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Minimum | Prime Rate or Federal Funds Rate | Refinanced Term Loan
Debt Instrument [Line Items]
Applicable margin over base rate						2.00%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Line of Credit
Debt Instrument [Line Items]
Debt instrument face amount						411.4
Credit facility refinanced amount						793.1
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Line of Credit | LIBOR
Debt Instrument [Line Items]
Applicable margin over base rate						3.00%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Line of Credit | Prime Rate or Federal Funds Rate
Debt Instrument [Line Items]
Applicable margin over base rate						2.00%
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Line of Credit | Minimum
Debt Instrument [Line Items]
Extended period of amortization on deferred financing fees						2014
Senior Secured Credit Facility Term B-2 Loan, variable, due 2017 | Line of Credit | Maximum
Debt Instrument [Line Items]
Extended period of amortization on deferred financing fees						2017
Senior Secured Credit Facility Term B-1 Loan, variable, due 2014
Debt Instrument [Line Items]
Senior Secured Credit Facility Term loan, due date						2014-08
Senior Notes, fixed 7.125%, due 2019
Debt Instrument [Line Items]
Total long-term debt	471.3	471.3					471.3
Interest rate of Senior Notes	7.13%
Debt instrument face amount	$500
Debt instrument, due date	2019
Senior Notes, fixed 7.125%, due 2019 | Allison Transmission Inc.
Debt Instrument [Line Items]
Interest rate of Senior Notes	7.13%

Summary_of_Companys_Interest_R

Summary of Company's Interest Rate Derivatives (Detail) (Derivatives not designated as hedging instruments, USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]
Notional Amount	$750		$1,450
Fair Value	-14.4		-18
3.75% Interest Rate Swap H, Aug 2011 - Aug 2014
Derivatives, Fair Value [Line Items]
Notional Amount			350
Fair Value			-7.2
3.77% Interest Rate Swap I, Aug 2011 - Aug 2014
Derivatives, Fair Value [Line Items]
Notional Amount			350
Fair Value			-7.2
2.96% Interest Rate Swap J, Aug 2013 - Aug 2014
Derivatives, Fair Value [Line Items]
Notional Amount			125
Fair Value			-2
3.05% Interest Rate Swap K, Aug 2013 - Aug 2014
Derivatives, Fair Value [Line Items]
Notional Amount			125
Fair Value			-2
3.44% Interest Rate Swap L, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	75	[1]	75	[1]
Fair Value	-2.3	[1]	-0.4	[1]
3.43% Interest Rate Swap M, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	100	[1]	100	[1]
Fair Value	-3	[1]	-0.4	[1]
3.37% Interest Rate Swap N, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	75	[1]	75	[1]
Fair Value	-2.1	[1]	-0.2	[1]
3.19% Interest Rate Swap O, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	75	[1]	75	[1]
Fair Value	-1.7	[1]	0.2	[1]
3.08% Interest Rate Swap P, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	75	[1]	75	[1]
Fair Value	-1.5	[1]	0.4	[1]
2.99% Interest Rate Swap Q, Aug 2016 - Aug 2014
Derivatives, Fair Value [Line Items]
Notional Amount	50	[1]	50	[1]
Fair Value	-0.9	[1]	0.4	[1]
2.98% Interest Rate Swap R, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	50	[1]	50	[1]
Fair Value	-0.9	[1]	0.4	[1]
2.73% Interest Rate Swap S, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	50	[1]
Fair Value	-0.5	[1]
2.74% Interest Rate Swap T, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	75	[1]
Fair Value	-0.8	[1]
2.66% Interest Rate Swap U, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	50	[1]
Fair Value	-0.4	[1]
2.60% Interest Rate Swap V, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	50	[1]
Fair Value	-0.3	[1]
2.40% Interest Rate Swap W, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Notional Amount	25	[1]
Fair Value	$0	[1]
[1]	includes LIBOR floor of 1.00%

Summary_of_Companys_Interest_R1

Summary of Company's Interest Rate Derivatives (Parenthetical) (Detail) (Derivatives not designated as hedging instruments)	Dec. 31, 2014	Dec. 31, 2013
LIBOR
Derivatives, Fair Value [Line Items]
LIBOR floor	1.00%	1.00%
3.75% Interest Rate Swap H, Aug 2011 - Aug 2014
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.75%	3.75%
3.77% Interest Rate Swap I, Aug 2011 - Aug 2014
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.77%	3.77%
2.96% Interest Rate Swap J, Aug 2013 - Aug 2014
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.96%	2.96%
3.05% Interest Rate Swap K, Aug 2013 - Aug 2014
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.05%	3.05%
3.44% Interest Rate Swap L, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.44%	3.44%
3.43% Interest Rate Swap M, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.43%	3.43%
3.37% Interest Rate Swap N, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.37%	3.37%
3.19% Interest Rate Swap O, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.19%	3.19%
3.08% Interest Rate Swap P, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	3.08%	3.08%
2.99% Interest Rate Swap Q, Aug 2016 - Aug 2014
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.99%	2.99%
2.98% Interest Rate Swap R, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.98%	2.98%
2.73% Interest Rate Swap S, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.73%	2.73%
2.74% Interest Rate Swap T, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.74%	2.74%
2.66% Interest Rate Swap U, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.66%	2.66%
2.60% Interest Rate Swap V, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.60%	2.60%
2.40% Interest Rate Swap W, Aug 2016 - Aug 2019
Derivatives, Fair Value [Line Items]
Derivative, Fixed Interest Rate	2.40%	2.40%

Derivatives_Additional_Informa

Derivatives - Additional Information (Detail) (Derivatives not designated as hedging instruments, USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative [Line Items]
Amount of collateral recorded in Other current assets	$0	$1.70
Foreign currency contracts | Other current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	-0.3	-0.3
Commodity contracts | Other current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	-0.6	-1.5
Commodity contracts | Other current assets
Derivative [Line Items]
Derivative Assets, Fair Value		0.1
Commodity contracts | Other non-current assets
Derivative [Line Items]
Derivative Assets, Fair Value		0
Commodity contracts | Other non-current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	-0.1	-0.2
Interest rate contracts | Other current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value		-18.5
Interest rate contracts | Other non-current assets
Derivative [Line Items]
Derivative Assets, Fair Value		1.5
Interest rate contracts | Other non-current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	($14.40)	($1)

Summary_of_Outstanding_Foreign

Summary of Outstanding Foreign Currency Forward Contracts (Detail) (Derivatives not designated as hedging instruments)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013
In Millions, unless otherwise specified	USD ($)	USD ($)	Foreign currency contracts	Foreign currency contracts	Foreign currency contracts	Foreign currency contracts	Foreign currency contracts	Foreign currency contracts
			USD ($)	USD ($)	Japanese Yen	Japanese Yen	Japanese Yen	Japanese Yen
					USD ($)	JPY (¥)	USD ($)	JPY (¥)
Derivatives, Fair Value [Line Items]
Assets Fair Value			($0.30)		($0.30)
Liabilities Fair Value				-0.3			-0.3
Notional Amount	$750	$1,450				¥ 300		¥ 600

Summary_of_Outstanding_Commodi

Summary of Outstanding Commodity Swaps (Detail) (Derivatives not designated as hedging instruments, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	t	t
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount	$750	$1,450
Fair value	-15.4	-19.9
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Fair value	-0.7	-1.6
Commodity contracts | Aluminum
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount	11.3	23.8
Quantity	6,200	11,875
Fair value	-0.7	-1.6
Commodity contracts | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount	0.2	0.3
Quantity	60,000	90,000
Fair value	$0	$0

Companys_Derivative_Instrument

Company's Derivative Instruments and their Impact on Financial Condition of Company (Detail) (Derivatives not designated as hedging instruments, USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative [Line Items]
Total derivatives not designated as hedging instruments	($15.40)	($19.90)
Foreign currency contracts | Other current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	-0.3	-0.3
Commodity contracts
Derivative [Line Items]
Total derivatives not designated as hedging instruments	-0.7	-1.6
Commodity contracts | Other current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	-0.6	-1.5
Commodity contracts | Other current and non-current assets
Derivative [Line Items]
Derivative Assets, Fair Value		0.1
Commodity contracts | Other current and non-current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	-0.7	-1.7
Commodity contracts | Other non-current assets
Derivative [Line Items]
Derivative Assets, Fair Value		0
Interest rate contracts | Other current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value		-18.5
Interest rate contracts | Other current and non-current liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	-14.4	-19.5
Interest rate contracts | Other non-current assets
Derivative [Line Items]
Derivative Assets, Fair Value		$1.50

Impact_on_the_Companys_Results

Impact on the Company's Results of Operations Related to Unrealized Gain (Loss) on Interest Rate Derivatives (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Unrealized gain on derivatives	$4.70	$32.80	$26.20
Derivatives not designated as hedging instruments | Interest rate contracts | Interest expense
Derivative [Line Items]
Unrealized gain on derivatives	$3.50	$34.30	$25.50

Product_Warranty_Liability_Act

Product Warranty Liability Activities (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Guarantor Obligations [Line Items]
Beginning balance	$90.50	$109.70	$115.40
Payments	-35	-38.7	-47.3
Increase in liability (warranty issued during period)	26.8	28.4	25.5
Net adjustments to liability	0.7	-9.6	15.3
Accretion (for Predecessor liabilities)	0.6	0.7	0.8
Ending balance	$83.60	$90.50	$109.70

Product_Warranty_Liabilities_A

Product Warranty Liabilities - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2007	Dec. 31, 2011
Guarantor Obligations [Line Items]
Product warranty liability, current	$24	$37.40
Product warranty liability, non-current	59.6	53.1
Increase (decrease) in extended Product liability	3.9	8.2	-7.9
Product warranty accrual reduction charged to DPIM receivable			7.3
Product warranty accrual reduction charged to comprehensive income	-1	2.4	0.6
Warranty liability	83.6	90.5	109.7		115.4
Warranty claims paid	35	38.7	47.3
Product warranty accrual additional reserve			10
Extended Product warranty, charge to the Consolidated Statements of Comprehensive Income (Loss)			10
General Motors
Guarantor Obligations [Line Items]
Product warranty accrual reduction charged to DPIM receivable	2.9	5.8
Reimbursement received	14.9	9.1
Dual Power Inverter Module
Guarantor Obligations [Line Items]
Product warranty, qualified cost				12
Product warranty, qualified cost sharing ratio				33.30%
Warranty liability	48.5	44.6
Warranty claims paid	32.8	25.5
Dual Power Inverter Module | General Motors
Guarantor Obligations [Line Items]
Product warranty, qualified cost				34
Product warranty, qualified cost sharing ratio				66.70%
Other receivable	28.7	25.8
Dual Power Inverter Module | Product Warranty
Guarantor Obligations [Line Items]
Product warranty, qualified cost				$46

Deferred_Revenue_Additional_In

Deferred Revenue - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Revenue [Line Items]
Deferred revenue current liabilities	$20.60	$29.20
Deferred revenue non-current liabilities	48.7	43.2
Deferred revenue recognized	8.8
Extended Transmission Coverage
Deferred Revenue [Line Items]
Deferred revenue current liabilities	20.3	20.4
Deferred revenue non-current liabilities	48.7	43.2
Deferred revenue recognized	20.8	21	19.9
U S Government Contracts
Deferred Revenue [Line Items]
Deferred revenue current liabilities	0.3	8.8	0.7
Deferred revenue recognized	$8.80

Deferred_Revenue_for_ETC_Activ

Deferred Revenue for ETC Activity (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Revenue [Line Items]
Revenue earned	($8.80)
Extended Transmission Coverage
Deferred Revenue [Line Items]
Beginning balance	63.6	63.5	60.5
Increases	26.2	21.1	22.9
Revenue earned	-20.8	-21	-19.9
Ending balance	$69	$63.60	$63.50

Other_Expense_Net_Detail

Other Expense Net (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of Other Income (Expense) [Line Items]
Loss on intercompany foreign exchange	($5.40)	($2.30)
Grant program income	2.6	5.2	11.5
Impairment loss on investments in technology-related initiatives	-2	-5	-14.4
Gain on negotiation of commercial agreement	2
Public offering fees and expenses	-1.4	-1.6	-6.1
Unrealized gain (loss) on derivative contracts (see NOTE 8)	1.2	-1.5	0.9
Realized loss on derivative contracts (see NOTE 8)	-1	-2.8	-1.3
Loss on foreign exchange	-1	-2.4	-2.6
Loss on repayments and repurchases of long-term debt (see NOTE 7)	-0.5	-0.8	-22.1
Termination of services agreement			-16
Loss on re-measurement of employee benefit plans (see NOTE 13)			-2.3
Other	-0.1	0.3	-0.4
Total	($5.60)	($10.90)	($52.80)

Other_Expense_Net_Additional_I

Other Expense, Net - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income Expense [Line Items]
Loss on intercompany foreign exchange	$5.40	$2.30
Payment for expansion of transmission technologies	$2	$5	$14.40

Other_Current_Liabilities_Deta

Other Current Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other Current Liabilities [Line Items]
Payroll and related costs	$50.90	$32.70
Sales allowances	25.5	26.9
Defense price reduction reserve	16.2	26.8
Vendor buyback obligation	13.2	11.8
Taxes payable	8.5	8.6
Accrued interest payable	5.2	11.2
Derivative liabilities	0.8	20.2
Other accruals	11.4	14.1
Total	$131.70	$152.30

Employee_Benefit_Plans_Additio

Employee Benefit Plans - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2014	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Actuarial gain (loss)				$17.90
Non-cash settlement charge		2.3
Reduction in pension liability		4.2
Excise tax as a percentage of value of plan that exceeds the threshold amount			40.00%
Effect of excise tax on post-retirement benefit obligation			4
Agreement period under post-retirement health care benefits	5 years
Favorable adjustment to benefit obligation	-28.9
Collective bargaining agreement, expiration period	2017-11		2017-11
Accumulated benefit obligation			129.7		103.1
Nonqualified Deferred Compensation Plan
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Deferred compensation expense			0.2		0.3	0.1
Quoted Prices in Active Markets for Identical Assets (Level 1) | Nonqualified Deferred Compensation Plan
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Plan assets, fair value			2.9		2.9
Plan obligation, fair value			1.3		1.3
Salary Plan
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Defined contribution plan expense			5.4		5.4	5.1
Defined contribution plan, employer contribution for employee with severance date on or after January 1, 1993			1.00%
Defined contribution plan, employer matching contribution			4.00%
Future Post Retirement Medical Care Costs
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Health care cost trend rate			6.70%
Health care cost ultimate trend rate			4.50%
Health care cost ultimate trend year			2027
Future Post Retirement Prescription Drug Costs
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Health care cost trend rate			6.00%
Health care cost ultimate trend rate			4.50%
Health care cost ultimate trend year			2027
Hourly Plan
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Defined benefit plan, service period before normal retirement age			30 years
Defined contribution plan expense			1.3		1	0.9
Post-retirement Benefits
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Actuarial gain (loss)			7.8		-30.7	3.8
Net benefit obligation	142.6		136	156.6	120.7	142.6
Deferred compensation obligation, additional recorded as a result of updated mortality assumption			4.1
Favorable adjustment to benefit obligation						-28.9
Pension Plans
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Actuarial gain (loss)			10.9		-16.9	3.5
Net benefit obligation	103.3		133.5	99.7	105.9	103.3
Deferred compensation obligation, additional recorded as a result of updated mortality assumption			2.9
Asset Purchase Agreement
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Plan assets transferred		18.8
Hourly Employee | Post-retirement Benefits
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Net benefit obligation			$136		$120.70

Employee_Benefit_Plans_Detail

Employee Benefit Plans (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Employee Benefit Plans [Line Items]
Total recognized - other comprehensive income	$9.10	($29)	($15.10)
Pension Plans
Schedule of Employee Benefit Plans [Line Items]
Service cost	13.2	16.3	15.2
Interest cost	5	4	4.1
Expected return on assets	-7.7	-6.7	-5.9
Prior service cost	0.1	0.1	0.1
Loss (gain)		0.7	1.2
Settlement loss			2.3
Net Periodic Benefit Cost	10.6	14.4	17
Net loss (gain)	2.1	-18.4	-2.1
Amortizations	-0.1	-0.8	-3.6
Total recognized - other comprehensive income	2	-19.2	-5.7
Post-retirement Benefits
Schedule of Employee Benefit Plans [Line Items]
Service cost	2.2	3.3	3.9
Interest cost	5.9	5.8	7.2
Prior service cost	-3.6	-3.6
Loss (gain)	-0.7
Net Periodic Benefit Cost	3.8	5.5	11.1
Prior service credit			-28.9
Net loss (gain)	7.8	-30.7	3.8
Amortizations	4.3	3.6
Total recognized - other comprehensive income	$12.10	($27.10)	($25.10)

WeightedAverage_Actuarial_Assu

Weighted-Average Actuarial Assumptions Used to Determine Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.80%	3.90%	4.60%
Rate of compensation increase (salaried)	3.00%	3.00%	4.00%
Expected return on assets	6.80%	7.00%	7.00%
Post-retirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.90%	4.10%	4.60%

WeightedAverage_Actuarial_Assu1

Weighted-Average Actuarial Assumptions Used to Determine Benefit Obligations (Detail)	Dec. 31, 2014	Dec. 31, 2013
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.90%	4.80%
Rate of compensation increase (salaried)	3.00%	3.00%
Post-retirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.00%	4.90%

Health_Care_Costs_Trends_Detai

Health Care Costs Trends (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Effect of 1% increase on total of service and interest cost	$1.70
Effect of 1% increase on post-retirement benefit obligation	28.6
Effect of 1% decrease on total of service and interest cost	-1.3
Effect of 1% decrease on post-retirement benefit obligation	($22.30)

Reconciliation_of_Changes_in_N

Reconciliation of Changes in Net Benefit Obligations and Fair Value of Plan Assets (Detail) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Benefit Obligations:
Plan Amendments	($28.90)
Actuarial loss (gain)		17.9
Pension Plans
Benefit Obligations:
Net benefit obligation at beginning of year			105.9	103.3	99.7
Service cost			13.2	16.3	15.2
Interest cost			5	4	4.1
Settlements					-18.8
Benefits paid			-1.5	-0.8	-0.4
Actuarial loss (gain)			10.9	-16.9	3.5
Net benefit obligation at end of year	103.3		133.5	105.9	103.3
Fair Value of Plan Assets:
Fair value of plan assets at beginning of year			108.6	89.4	83.4
Actual return on plan assets			16.4	8.2	11.5
Employer contributions			11.8	11.8	13.7
Settlements					-18.8
Benefits paid			-1.5	-0.8	-0.4
Fair value of plan assets at end of year	89.4		135.3	108.6	89.4
Net Funded Status	-13.9		1.8	2.7	-13.9
Post-retirement Benefits
Benefit Obligations:
Net benefit obligation at beginning of year			120.7	142.6	156.6
Service cost			2.2	3.3	3.9
Interest cost			5.9	5.8	7.2
Plan Amendments					-28.9
Benefits paid			-0.6	-0.3
Actuarial loss (gain)			7.8	-30.7	3.8
Net benefit obligation at end of year	142.6		136	120.7	142.6
Fair Value of Plan Assets:
Employer contributions			0.6	0.3
Benefits paid			-0.6	-0.3
Net Funded Status	($142.60)		($136)	($120.70)	($142.60)

Fair_Value_of_Plan_Assets_by_A

Fair Value of Plan Assets by Asset Category (Detail) (Quoted Prices in Active Markets for Identical Assets (Level 1), USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	$135.30	$108.60
Percentage of plan assets	100.00%	100.00%
Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	8.6	3.6
Percentage of plan assets	6.00%	3.00%
Diversified equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	57.8	51.5
Percentage of plan assets	43.00%	48.00%
Diversified debt Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	$68.90	$53.50
Percentage of plan assets	51.00%	49.00%

Plan_Asset_Allocation_Detail

Plan Asset Allocation (Detail)	12 Months Ended
	Dec. 31, 2014
Hourly Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	100.00%
Hourly Plan | Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	5.00%
Hourly Plan | Diversified equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	39.00%
Hourly Plan | Diversified debt Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	56.00%
Salary Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	100.00%
Salary Plan | Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	8.00%
Salary Plan | Diversified equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	46.00%
Salary Plan | Diversified debt Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation	46.00%

Amounts_Recognized_in_Balance_

Amounts Recognized in Balance Sheet and Accumulated Other Comprehensive Income AOCI (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Pension Plans
Amounts Recognized in Balance Sheet:
Noncurrent assets	$7.90	$7.40
Noncurrent liabilities	-6.1	-4.7
Total asset (liability)	1.8	2.7	-13.9
Accumulated Other Comprehensive Loss:
Prior service (cost) credit	-0.1	-0.2
Actuarial gain	0.6	2.7
Total	0.5	2.5
Post-retirement Benefits
Amounts Recognized in Balance Sheet:
Current liabilities	-1.2	-1.4
Noncurrent liabilities	-134.8	-119.3
Total asset (liability)	-136	-120.7	-142.6
Accumulated Other Comprehensive Loss:
Prior service (cost) credit	21.7	25.4
Actuarial gain	8.6	17.1
Total	$30.30	$42.50

Amounts_in_Accumulated_Other_C

Amounts in Accumulated Other Comprehensive Income AOCI Expected to be Amortized and Recognized as Component of Net Periodic Benefit Cost in Two Thousand Thirteen (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service (cost) credit	($1)
Actuarial loss	1
Total	0
Post-retirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service (cost) credit	3.6
Total	$3.60

Projected_and_Accumulated_Bene

Projected and Accumulated Benefit Obligation and Fair Value of Plan Assets for Pension Plans with Projected Benefit Obligation in Excess of Plan Assets (Detail) (Salary Plan, USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Salary Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	$71.40	$53.80
Fair value of plan assets	65.3	49.1
Accumulated benefit obligation	67.6	50.9
Fair value of plan assets	$65.30	$49.10

Expected_Cash_Flows_for_Pensio

Expected Cash Flows for Pension and Post-Retirement Benefit Plans (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Pension Plans
Employer Contributions:
2015 expected contributions	$2
Expected Benefit Payments:
2015	2.3
2016	3
2017	3.8
2018	4.6
2019	5.5
2020-2024	40.6
Post-retirement Benefits
Employer Contributions:
2015 expected contributions	1.2
Expected Benefit Payments:
2015	1.2
2016	1.7
2017	2.4
2018	3.2
2019	3.9
2020-2024	$27.70

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 24, 2012	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares of common stock available for issuance under the 2011 Plan						15,300,000
Common stock conversion ratio for each RSU upon vesting		1
Unrecognized compensation cost, expected period for recognition		2 years
Incentive compensation expense		$3.30	$1.70	$5.50
Taxes paid related to net share settlement of equity awards		8.4	3.6
Option expiration period		10 years
Dividend per-share	$0.15	$0.51	$0.42	$0.18
Weighted-average grant-date fair value of options granted		$9.51	$9.76	$0
Total fair value of stock options vested		0	0.7	7.5
Total intrinsic value of stock options exercised		82.3	58	24.6
Aggregate intrinsic value of stock options outstanding	80.4	80.4	106.8
Aggregate intrinsic value of stock options exercisable	72.5	72.5	103.8
Unrecognized compensation cost related to non-vested share-based compensation arrangements	4.8	4.8	4.2	0.5
For reason other than death or disability
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period following optionees' termination options cease to be exercisable		90 days
Termination for retirement after the age of 65
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period following optionees' termination options cease to be exercisable		3 years
Termination Due To Death
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period following optionees' termination options cease to be exercisable		12 months
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting percentage on each anniversary of grant date	100.00%	100.00%
Option Vesting period		2 years
Employee Stock Option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting percentage on each anniversary of grant date	20.00%	20.00%
Option Vesting period		3 years
Employee Stock Option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting percentage on each anniversary of grant date	33.00%	33.00%
Option Vesting period		5 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	3	3	10.4
Unrecognized compensation cost, expected period for recognition		2 years
Incentive compensation expense		9.8	12	0.9
Total fair value of RSUs vested		20.2	9		0
Number of shares paying for withholding taxes		300,000	100,000
Taxes paid related to net share settlement of equity awards		8.4	3.6
Restricted Stock Units (RSUs) | Vesting Schedule One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting term		1 year
Restricted Stock Units (RSUs) | Vesting Schedule Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting term		2 years
Restricted Stock Units (RSUs) | Vesting Schedule Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting term		3 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	3.4	3.4
Unrecognized compensation cost, expected period for recognition		2 years
Incentive compensation expense		$1.60
Restricted Stock | Vesting Schedule One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting term		1 year
Restricted Stock | Vesting Schedule Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting term		2 years
Restricted Stock | Vesting Schedule Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting term		3 years

Summary_of_RSU_Activity_Detail

Summary of RSU Activity (Detail) (Restricted Stock Units (RSUs), USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock Units (RSUs)
Non-vested RSUs:
Beginning balance	0.8	1
Granted	0	0.2	1
Vested	-0.6	-0.4
Forfeited	0	0	0
Ending balance	0.2	0.8	1
Weighted-Average Grant-Date Fair Value
Beginning balance	$20.90	$20.20
Granted	$29.85	$23.31	$20.20
Vested	$20.32	$20.23
Forfeited	$0	$0	$0
Ending balance	$26.57	$20.90	$20.20

Summary_of_Restricted_Stock_Ac

Summary of Restricted Stock Activity (Detail) (Restricted Stock, USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014
Restricted Stock
Non-vested Shares:
Granted	0.2
Vested	0
Forfeited	0
Ending balance	0.2
Weighted-Average Grant-Date Fair Value
Granted	$29.47
Vested	$0
Forfeited	$0
Ending balance	$29.47

Assumptions_Used_to_Calculate_

Assumptions Used to Calculate Fair Value of Options (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	38.00%	51.00%
Expected dividend yield	1.60%	1.20%
Expected term (in years)	5 years 6 months	5 years 4 months 24 days	0 years
Expected forfeitures	0.00%	0.00%
Risk-free rate	1.70%	1.60%

Option_Activity_Detail

Option Activity (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Options
Outstanding stock options, beginning balance	8.7	11.9	14.9
Granted	0.4	0.6
Exercised	-4.2	-3.8	-2.7
Forfeited or expired			-0.3
Outstanding stock options, ending balance	4.9	8.7	11.9	14.9
Exercisable stock options	3.9	8.1	11.8	11.5
Weighted-Average Exercise
Outstanding stock options	$15.33	$14.01	$13.40
Granted	$30.23	$23.39
Exercised	$0	$0	$0
Forfeited or expired	$0	$0	$0
Outstanding stock options	$17.49	$15.33	$14.01	$13.40
Exercisable stock options	$15.32	$14.79	$14.02	$13.37
Weighted-Average Remaining
Outstanding stock options	4 years 2 months 9 days	4 years 3 months 18 days	4 years 11 months 5 days	4 years 11 months 9 days
Exercisable stock options	3 years 29 days	3 years 11 months 9 days	4 years 10 months 28 days	4 years 10 months 17 days

NonVested_Shares_Activity_Deta

Non-Vested Shares Activity (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Non-vested Stock Options:
Beginning Balance	0.6	0.2	3.4
Granted	0.4	0.6
Vested		-0.2	-2.9
Forfeited			-0.3
Ending Balance	1	0.6	0.2
Weighted-Average Grant-Date
Beginning Balance	$9.06	$4.34	$2.81
Granted	$9.51	$9.76
Vested		$3.59	$2.58
Forfeited			$4
Ending Balance	$9.44	$9.06	$4.34

Income_Before_Income_Taxes_Det

Income Before Income Taxes (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]
U.S. income	$355.10	$259	$204.10
Foreign income	13	7.1	12.1
Total	$368.10	$266.10	$216.20

Provision_for_Income_Tax_Expen

Provision for Income Tax Expense (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Estimated current income taxes:
U.S. federal	$1.60	$0.20	$1.50
Foreign	6.3	1.9	3.9
U.S. state and local	-0.2	0.6	0.4
Total Current	7.7	2.7	5.8
Deferred income tax expense (credit), net:
U.S. federal	125.6	87.6	-282.5
Foreign	-0.3	0.1	0.1
U.S. state and local	6.5	10.3	-21.4
Total Deferred	131.8	98	-303.8
Total income tax expense (benefit)	$139.50	$100.70	($298)

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Income taxes paid	$5	$3.80	$10.70
Net operating loss carryforwards, federal	91.00%
Net operating loss carryforwards, state	9.00%
Operating loss carryforwards	253.3
Valuation allowances	$5.20	$2.80
Minimum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year	2027
Maximum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year	2032

Reconciliation_of_Provision_fo

Reconciliation of Provision for Income Tax Expense (Benefit) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Provision of Income Taxes [Line Items]
Tax at U.S. statutory income tax rate	$128.90	$93.10	$75.70
Foreign rate differential	-2.3	-0.7	-2.6
Non-deductible expenses	3.9	0.8	4.2
Valuation allowance	2.6	1	-384.1
State tax expense	4	7.3	5.7
Adjustment to deferred tax expense	2.4	-0.3	2.2
Other adjustments	0	-0.5	0.9
Total income tax expense (benefit)	$139.50	$100.70	($298)

Deferred_Tax_Assets_and_Liabil

Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Deferred tax assets:
Inventories	$5.10	$4.60
Warranty accrual	30.5	32.7
Sales allowances and rebates	6.7	7.9
Deferred revenue	25.7	24
Post-retirement health care	5.7
Intangibles	77.3	83.6
Other accrued liabilities	32.7	27.2
Unrealized loss on interest rate derivatives	5.7	3.7
Operating loss carryforwards	107.8	140.7
Stock based compensation	6.9	12.5
Technology-related investments	6.6	6.8
Loan fees		0.9
Other	16.4	10.4
Total Deferred tax assets	327.1	355
Valuation allowances	-5.2	-2.8
Deferred tax liabilities:
Property, plant and equipment	-20.2	-22
Goodwill	-320.8	-280.3
Product warranty liabilities	-4.3	-5.6
Pension		-0.5
Post-retirement health care		-0.2
Other	-3.5
Total Deferred tax liabilities	-439.1	-369.2
Net Deferred tax liability	-117.2	-17
Trade Name
Deferred tax liabilities:
Trade name	($90.30)	($60.60)

Liability_for_Unrecognized_Tax

Liability for Unrecognized Tax Benefit (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Beginning Balance	$2.30
Increases in unrecognized tax benefits as a result of current year activity	0.2
Unrecognized Tax Benefits, Ending Balance	$2.50

Changes_in_Components_of_Accum

Changes in Components of Accumulated Other Comprehensive Loss (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Comprehensive Income (Loss) [Line Items]
Beginning balance	$30.30	($9.20)	($33.20)
Foreign currency translation, before tax	-7.4	-5	-0.7
Pension and OPEB liability adjustment, before tax	-14.6	46.4	26.7
Available-for-sale securities, before tax	-3.2	-1.9	-2
Net current period other comprehensive income (loss)	-25.2	39.5	24
Ending balance	5.1	30.3	-9.2
Beginning balance	-51.3	-34.7	-23.8
Foreign currency translation, tax expense	0	0	0
Pension and OPEB liability adjustment, tax expense	5.5	-17.4	-11.6
Available-for-sale securities, tax expense	1.2	0.8	0.7
Net current period other comprehensive income (loss)	6.7	-16.6	-10.9
Ending balance	-44.6	-51.3	-34.7
Beginning Balance	-21	-43.9	-57
Foreign currency translation, after tax	-7.4	-5	-0.7
Pension and OPEB liability adjustment, after tax	-9.1	29	15.1
Available-for-sale securities, after tax	-2	-1.1	-1.3
Total other comprehensive (loss) income, net of tax	-18.5	22.9	13.1
Ending balance	($39.50)	($21)	($43.90)

Consolidated_Statement_of_Comp

Consolidated Statement of Comprehensive Income Affected by Reclassification from AOCL (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, 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
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales									($1,151.50)	($1,084.90)	($1,187.50)
Selling, general and administrative expenses									-344.6	-334.9	-419
Engineering - research and development									-103.8	-97.1	-115.1
Income before income taxes	77.8	116.3	94.7	79.3	67.5	72.4	81.8	44.4	368.1	266.1	216.2
Income tax (expense) benefit									-139.5	-100.7	298
Total reclassifications	50.5	68.8	57.2	52.1	42.9	44.5	50.5	27.5	228.6	165.4	514.2
Reclassified from AOCL | Prior service cost
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales									3.2
Selling, general and administrative expenses									0.3
Engineering - research and development									0.1
Reclassified from AOCL | Actuarial loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales									0.7
Selling, general and administrative expenses									0
Engineering - research and development									0
Reclassified from AOCL | Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income taxes									4.3
Income tax (expense) benefit									-1.6
Total reclassifications									$2.70

Recovered_Sheet3

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Line Items]
Rent expense	$5.40	$5.70	$5.50

Future_Payments_under_NonCance

Future Payments under Non-Cancelable Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Operating Leased Assets [Line Items]
2015	$4.60
2016	2.8
2017	1.7
2018	0.8
2019	0.6
Thereafter	2
Total	$12.50

Concentration_of_Risk_Addition

Concentration of Risk - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
		Employee		Customer
Concentration Risk [Line Items]
Number of employees		2,700	2,700
Collective bargaining agreement, expiration date	2017-11	2017-11
Employees in the U.S
Concentration Risk [Line Items]
Concentration risk, percentage		90.00%	90.00%
Unionized employees subject to collective bargaining agreement
Concentration Risk [Line Items]
Concentration risk, percentage		60.00%	60.00%
Sales Revenue, Goods, Net
Concentration Risk [Line Items]
Number of significant customers	3	3	3	3
Accounts Receivable
Concentration Risk [Line Items]
Number of significant customers		3	3
Supplier Concentration Risk
Concentration Risk [Line Items]
Number of significant suppliers		1	1	1

Customers_Accounted_for_Greate

Customers Accounted for Greater Than Ten Percent of Net Sales (Detail) (Sales Revenue, Goods, Net)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Daimler AG
Concentration Risk [Line Items]
Concentration risk, percentage	17.00%	17.00%	13.00%
Navistar Inc
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%	10.00%	11.00%
Oshkosh Corporation
Concentration Risk [Line Items]
Concentration risk, percentage	4.00%	8.00%	11.00%

Customers_Accounted_for_Greate1

Customers Accounted for Greater Than Ten Percent of Accounts Receivable (Detail) (Accounts Receivable)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Daimler AG
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%	15.00%
A B Volvo
Concentration Risk [Line Items]
Concentration risk, percentage	8.00%	11.00%
Navistar Inc
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	10.00%

Supplier_Accounted_for_Greater

Supplier Accounted for Greater Than Ten Percent of Materials Purchased (Detail) (Supplier Concentration Risk, Linamar Corporation Inc.)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplier Concentration Risk | Linamar Corporation Inc.
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%	13.00%	13.00%

Recovered_Sheet4

Certain Relationships and Related Party Transactions - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended		12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Feb. 28, 2014	Dec. 31, 2013
Fixed 7.125% Senior Notes
Related Party Transaction [Line Items]
Senior Notes, stated interest rate	7.13%
Secondary Public Offering in September
Related Party Transaction [Line Items]
Secondary offering of common stock	5,392,499
Common stock, price per share	$30.46
Secondary Public Offering in June
Related Party Transaction [Line Items]
Secondary offering of common stock	40,250,000
Common stock, price per share	$29.95
Secondary Public Offering in April
Related Party Transaction [Line Items]
Secondary offering of common stock	25,000,000
Common stock, price per share	$29.78
Secondary Public Offering in February
Related Party Transaction [Line Items]
Secondary offering of common stock	28,750,000
Common stock, price per share	$29.17
Secondary Public Offering
Related Party Transaction [Line Items]
Stock repurchased from underwriter		5,000,000	3,428,179
Secondary Public Offering in August
Related Party Transaction [Line Items]
Secondary offering of common stock				23,805,000
Common stock, price per share				$21.18
Stock repurchased from underwriter				4,700,000
Secondary Public Offering in November
Related Party Transaction [Line Items]
Secondary offering of common stock				15,000,000
Common stock, price per share				$23.10
Secondary Public Offering in December
Related Party Transaction [Line Items]
Secondary offering of common stock				12,500,000
Common stock, price per share				$25.56
Lawrence E. Dewey | Fixed 7.125% Senior Notes
Related Party Transaction [Line Items]
Senior notes held by executive officers	$100,000
David S. Graziosi | Fixed 7.125% Senior Notes
Related Party Transaction [Line Items]
Senior notes held by executive officers	$450,000

Common_Stock_Additional_Inform

Common Stock - Additional Information (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Common Stock Disclosure [Line Items]
Common stock, repurchases authorized	$500
Common stock, remained available for stock repurchases	$500

Earnings_Per_Share_Additional_

Earnings Per Share - Additional Information (Detail)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive stock options not included in the diluted EPS computation	0

Reconciliation_of_Numerators_a

Reconciliation of Numerators and Denominators Used to Calculate Basic EPS and Diluted EPS (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, 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
Computation of Earnings Per Share [Line Items]
Net income	$50.50	$68.80	$57.20	$52.10	$42.90	$44.50	$50.50	$27.50	$228.60	$165.40	$514.20
Weighted average shares of common stock outstanding									179.8	184.5	182
Dilutive effect stock-based awards									2.5	3.4	4.2
Diluted weighted average shares of common stock outstanding									182.3	187.9	186.2
Basic earnings per share attributable to common stockholders	$0.28	$0.38	$0.32	$0.29	$0.24	$0.24	$0.27	$0.15	$1.27	$0.90	$2.83
Diluted earnings per share attributable to common stockholders	$0.28	$0.38	$0.31	$0.28	$0.23	$0.24	$0.26	$0.15	$1.25	$0.88	$2.76

Net_Sales_by_Country_Detail

Net Sales by Country (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, 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]
Total net sales	$544.40	$553.30	$536.10	$493.60	$491	$466.30	$512.10	$457.40	$2,127.40	$1,926.80	$2,141.80
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									1,578	1,354.30	1,509.60
CHINA
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									128.7	141	136.4
CANADA
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									85.1	88.6	123
JAPAN
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									45.8	37	52
GERMANY
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									38.1	53.9	39.1
UNITED KINGDOM
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									36.8	42.5	74.1
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									$214.90	$209.50	$207.60

Net_LongLived_Assets_by_Countr

Net Long-Lived Assets by Country (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$514.60	$563.40	$596.20
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	442.6	478.7	493.6
INDIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	51.5	59.9	76.8
HUNGARY
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	15.1	18.1	18.4
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$5.40	$6.70	$7.40

Recovered_Sheet5

Quarterly Financial Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, 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 [Line Items]
Net sales	$544.40	$553.30	$536.10	$493.60	$491	$466.30	$512.10	$457.40	$2,127.40	$1,926.80	$2,141.80
Gross profit	255.6	259.3	238.5	222.5	211.4	206.1	226.1	198.3	975.9	841.9	954.3
Operating income	117.8	147.3	132.2	114.8	99.6	111.2	117.7	81.4	512.1	409.9	420.2
Income before income taxes	77.8	116.3	94.7	79.3	67.5	72.4	81.8	44.4	368.1	266.1	216.2
Net income	$50.50	$68.80	$57.20	$52.10	$42.90	$44.50	$50.50	$27.50	$228.60	$165.40	$514.20
Basic earnings per share	$0.28	$0.38	$0.32	$0.29	$0.24	$0.24	$0.27	$0.15	$1.27	$0.90	$2.83
Diluted earnings per share	$0.28	$0.38	$0.31	$0.28	$0.23	$0.24	$0.26	$0.15	$1.25	$0.88	$2.76

Schedule_I_Parent_Company_Only

Schedule I Parent Company Only Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Current Assets:
Cash	$263	$184.70	$80.20	$314
Total Current Assets	758	606.9
TOTAL ASSETS	4,804.20	4,812.60
Current Liabilities:
Accounts payable	151.7	150.4
Total Current Liabilities	345.9	387.2
Capital stock	1,397.80	1,438.80	1,356.90	821.7
Additional paid-in-capital	1,651	1,631.80
Accumulated deficit	-215.5	-173.8
Accumulated other comprehensive loss, net of tax	-39.5	-21	-43.9	-57
TOTAL LIABILITIES & STOCKHOLDERS' EQUITY	4,804.20	4,812.60
Parent Company
Current Assets:
Cash	0	0	0	0
Total Current Assets	0	0
Investments in and advances to subsidiaries	1,397.80	1,438.80
TOTAL ASSETS	1,397.80	1,438.80
Current Liabilities:
Accounts payable	0	0
Total Current Liabilities	0	0
Capital stock	1.8	1.8
Additional paid-in-capital	1,651	1,631.80
Treasury stock	0	0
Accumulated deficit	-215.5	-173.8
Accumulated other comprehensive loss, net of tax	-39.5	-21
TOTAL LIABILITIES & STOCKHOLDERS' EQUITY	$1,397.80	$1,438.80

Schedule_I_Parent_Company_Only1

Schedule I Parent Company Only Statements of Comprehensive Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, 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
Condensed Financial Statements, Captions [Line Items]
Net sales	$544.40	$553.30	$536.10	$493.60	$491	$466.30	$512.10	$457.40	$2,127.40	$1,926.80	$2,141.80
Operating income	117.8	147.3	132.2	114.8	99.6	111.2	117.7	81.4	512.1	409.9	420.2
Other income:
Income before income taxes	77.8	116.3	94.7	79.3	67.5	72.4	81.8	44.4	368.1	266.1	216.2
Income tax expense									-139.5	-100.7	298
Net income	50.5	68.8	57.2	52.1	42.9	44.5	50.5	27.5	228.6	165.4	514.2
Comprehensive income									210.1	188.3	527.3
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0	0
General and administrative fees									0	0	0
Operating income									0	0	0
Other income:
Equity earnings of consolidated subsidiary									228.6	165.4	514.2
Income before income taxes									228.6	165.4	514.2
Income tax expense									0	0	0
Net income									228.6	165.4	514.2
Comprehensive income									$228.60	$165.40	$514.20

Recovered_Sheet6

Schedule I Parent Company only Statements of Cash Flows (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$228.60	$165.40	$514.20
Deduct items included in net income not providing cash:
Net cash provided by operating activities	556.9	453.5	497.5
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash used for investing activities	-67.9	-81.5	-138.7
CASH FLOWS FROM FINANCING ACTIVITIES:
Dividends	-91.6	-77.1	-32.8
Net cash used for financing activities	-424.1	-277.5	-593.5
Net increase (decrease) during period	78.3	104.5	-233.8
Cash and cash equivalents at beginning of period	184.7	80.2	314
Cash and cash equivalents at end of period	263	184.7	80.2
Parent Company
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	228.6	165.4	514.2
Deduct items included in net income not providing cash:
Equity in earnings in consolidated subsidiary	-228.6	-165.4	-514.2
Net cash provided by operating activities	0	0	0
CASH FLOWS FROM INVESTING ACTIVITIES:
Investments in subsidiaries	-59.6	-46.3	-29
Dividends	91.6	77.1	32.8
Net cash used for investing activities	32	30.8	3.8
CASH FLOWS FROM FINANCING ACTIVITIES:
Capital contributions	59.6	46.3	29
Dividends	-91.6	-77.1	-32.8
Net cash used for financing activities	-32	-30.8	-3.8
Net increase (decrease) during period	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	$0	$0	$0