STOCKHOLDERS' EQUITY Share Based Comp (Details 2) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended			0 Months Ended		12 Months Ended							0 Months Ended		12 Months Ended	0 Months Ended					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Mar. 28, 2012 Restricted stock awards	Mar. 01, 2012 Restricted stock awards	Dec. 31, 2012 Restricted stock awards	Dec. 31, 2011 Restricted stock awards	Dec. 31, 2010 Restricted stock awards	Dec. 31, 2012 Stock Options [Member]	Dec. 31, 2012 Stock Option [Member]	Dec. 31, 2011 Stock Option [Member]	Dec. 31, 2010 Stock Option [Member]	Mar. 22, 2011 All Company Stock Plans [Member]	Mar. 03, 2010 All Company Stock Plans [Member]	Dec. 31, 2012 All Company Stock Plans [Member]	Mar. 03, 2010 All Company Stock Plans [Member] Minimum [Member]	Mar. 03, 2010 All Company Stock Plans [Member] Maximum [Member]	Mar. 28, 2012 Market Condition Award [Member]	Mar. 01, 2012 Market Condition Award [Member]	Dec. 31, 2012 Restricted stock awards All Company Stock Plans [Member]	Dec. 31, 2012 Restricted stock awards Market Condition Award [Member]	Dec. 31, 2012 All Company Stock Plans [Member] Low end of range [Member]	Dec. 31, 2012 All Company Stock Plans [Member] Mid range [Member]	Dec. 31, 2012 All Company Stock Plans [Member] High end of range [Member]	Dec. 31, 2012 All Company Stock Plans [Member] Restricted stock awards	May 31, 1999 Terex Corporation Long-term Incentive Plan (the 1996 Plan) Member	Dec. 31, 2012 Terex Corporation 2009 Omnibus Incentive Plan (the 2009 Plan) Member	May 31, 2011 Terex Corporation 2009 Omnibus Incentive Plan (the 2009 Plan) Member	Apr. 30, 2011 Terex Corporation 2009 Omnibus Incentive Plan (the 2009 Plan) Member	May 31, 2011 Terex Corporation 2009 Omnibus Incentive Plan (the 2009 Plan) Member Maximum [Member]	May 31, 2004 Terex Corporation 2000 Incentive Plan (the 2000 Plan) Member	May 31, 2002 Terex Corporation 2000 Incentive Plan (the 2000 Plan) Member	Apr. 30, 2002 Terex Corporation 2000 Incentive Plan (the 2000 Plan) Member
Share-based compensation arrangements
Shares authorized for issuance (in shares)																										4,000,000		5,000,000	3,000,000	5,000,000	12,000,000	7,000,000	4,000,000
Shares available for grant (in shares)																											2,500,000
Shares vesting period (in years)									4 years													4 years	5 years	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grant Date Average Contractual Term									10 years
Shares granted during period (in shares)	0	0	0
Intrinsic value of options exercised (in dollars)										$ 0.2	$ 0.3	$ 0.3
Number of Options
Outstanding at the beginning of the period (in shares)											826,193
Exercised (in shares)										(291,369)
Canceled or expired (in shares)										(15,600)
Outstanding at the end of the period (in shares)										519,224		826,193
Exercisable at the end of the period (in shares)										519,224
Vested at the end of the period (in shares)										519,224
Weighted Average Exercise Price Per Share
Outstanding at the beginning of the period (in dollars per share)											$ 18.89
Exercised (in dollars per share)										$ 10.38
Canceled or expired (in dollars per share)										$ 41.19
Outstanding at the end of the period (in dollars per share)										$ 23.00		$ 18.89
Exercisable at the end of the period (in dollars per share)										$ 23.00
Vested at the end of the period (in dollars per share)										$ 23.00
Weighted Average Remaining Contractual Life (in years)
Outstanding at the end of the period (in years)										1 year 7 months 17 days
Exercisable at the end of the period (in years)										1 year 7 months 17 days
Vested at the end of the period (in years)										1 year 7 months 17 days
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)										5.6
Exercisable at the end of the period (in dollars)										5.6
Vested at the end of the period (in dollars)										5.6
Percentage of awards that vest over a four year period (as a percent)																									15.00%
Percentage of awards that vest on each of the first four anniversary dates of the grant (as a percent)																									25.00%
Percentage of awards that vest over a five year period (as a percent)																									20.00%
Percentage of awards that vest over a three year period (as a percent)																				65.00%
Percentage of awards that vest evenly over three year period (as a percent)																									60.00%
Percentage of awards that vest at end of three year period (as a percent)																									40.00%
Percentage of awards subject to performance conditions (as a percent)																									40.00%
Number of shares of restricted stock with fair value based on market condition, instead of market price (in shares)																					904,000
Assumptions used in valuation
Dividend yields (as a percent)				0.00%	0.00%								0.00%	0.00%
Expected volatility (as a percent)				56.83%	59.15%								80.29%	59.04%
Risk-free interest rate (as a percent)				0.47%	0.41%								1.04%	3.04%
Expected life (in years)				3 years	3 years								3 years	4 years
Weighted average fair value at date of grant for options granted (in dollars per share)						$ 25.74	$ 34.99	$ 20.18					$ 41.96			$ 16.17	$ 19.08
Unrecognized compensation costs (in dollars)						49.6
Weighted average period of unrecognized compensation costs will be recognized (in years)						1 year 10 months 24 days
Total fair value of shares vested (in dollars)						16.1	26.3	33.1
Shares of common stock contributed to employee stock trust	58,000
Restricted Stock Awards
Nonvested at the beginning of the period (in shares)						3,134,940
Granted (in shares)															1,482,752
Vested (in shares)															(948,207)
Canceled or expired (in shares)															(396,766)
Nonvested at the end of the period (in shares)							3,134,940								3,272,719
Weighted Average Grant Date Fair Value
Nonvested at the beginning of the period (in dollars per shares)															$ 22.91
Granted (in dollars per shares)															$ 25.74			$ 29.50	$ 32.58
Vested (in dollars per shares)															$ 16.94
Cancelled or expired (in dollars per shares)															$ 24.36
Nonvested at the end of the period (in dollars per shares)															$ 25.17
Compensation expense recognized under all stock-based compensation arrangements (in dollars)	29.8	23.6	45.3
Tax benefit related to stock-based compensation arrangements (in dollars)	9.1	7.1	14.1
Cash received from option exercises under all stock-based compensation arrangements (in dollars)	$ 1.3