Description of Business and Summary of Significant Accounting Policies (Details)		1 Months Ended	3 Months Ended	12 Months Ended			24 Months Ended
	Dec. 16, 2014	Jan. 31, 2015 USD ($)	Oct. 31, 2015 USD ($)	Jan. 31, 2016 USD ($) item $ / shares shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 USD ($) shares	Dec. 31, 2014 USD ($)	Jan. 07, 2016 USD ($)	Dec. 17, 2014 shares
Significant Accounting Policies [Line Items]
Ratio of shares of KLX received for shares of B/E Aerospace	0.5
Accounts receivable, Net
Accounts receivable - trade, allowance for doubtful accounts		$ 8,000,000		$ 11,300,000
Inventories
Inventory reserves		33,500,000		40,400,000
Provision for inventory with limited shelf life, maximum amount		500,000		$ 500,000			$ 500,000
Goodwill and Intangible Assets, Net
Number of reporting units | item				2
Goodwill impairment charge			$ 310,400,000	$ 310,400,000
Intangible assets impairment			177,800,000	$ 177,800,000
Property and equipment impairment			$ 152,000,000
Accounting for Stock Based Compensation
Unvested shares, distribution date conversion ratio	1.8139			1.8139
Qualified employees purchase of stock at a price equal to percentage of closing price				85.00%
Employee Stock Purchase Plan, rights granted				$ 300,000	$ 200,000	$ 200,000
Treasury Stock
Purchase of treasury stock				12,500,000
Recent Accounting Pronouncements
Current assets		2,124,800,000		$ 2,022,800,000
Senior Unsecured Notes 5.875 Percent Due 2022
Recent Accounting Pronouncements
Debt, interest rate				5.875%
Unamortized discount		22,800,000		$ 20,500,000
Accounting Standards Update 2015-17 | Adjustments for New Accounting Principle, Early Adoption
Recent Accounting Pronouncements
Current assets		(37,100,000)
Non current liability		(37,100,000)
KLX Inc Long Term Incentive Plan
Treasury Stock
Purchase of treasury stock (shares) | shares				32,122
Purchase of treasury stock				$ 1,000,000
Existing $250.0 Share Repurchase Program
Treasury Stock
Purchase of treasury stock (shares) | shares				416,200
Share repurchase program, authorized amount				$ 250,000,000				$ 100,000,000
Purchase of treasury stock				$ 11,400,000
Repurchased shares, average price per share | $ / shares				$ 27.48
Sales Revenues | Customer Concentration | Major Customer 1
Concentration of Risk
Concentration risk percentage						10.00%
Sales Revenues | Customer Concentration | Major Customer 2
Concentration of Risk
Concentration risk percentage						10.00%
Energy Services Group
Goodwill and Intangible Assets, Net
Goodwill impairment charge		0		$ 310,400,000	0	$ 0
Intangible assets impairment				177,800,000
Property and equipment impairment				152,000,000
Long-lived assets impairment		$ 0		$ 329,800,000	0	0
Minimum
Property and Equipment, Net
Property and equipment, useful lives (years)				1 year
Goodwill and Intangible Assets, Net
Intangible assets, useful lives				4 years
Maximum
Property and Equipment, Net
Property and equipment, useful lives (years)				50 years
Goodwill and Intangible Assets, Net
Intangible assets, useful lives				30 years
Options
Accounting for Stock Based Compensation
Compensation cost					$ 0	$ 0
Stock options granted | shares					0	0
BE Aerospace, former parent of the Company | Distribution of Stock of Subsidiary to Stockholders to Effect Spin-Off
Significant Accounting Policies [Line Items]
Shares Issued | shares									52,500,000
Ratio of shares of KLX received for shares of B/E Aerospace	0.5