- Definition

Description of the terms and benefits provided by the employer's defined contribution plans. A defined contribution plan provides benefits in return for services rendered, provides an individual account for each participant, and has terms that specify how contributions to the individual's account are to be determined rather than the amount of benefits the individual is to receive. Under a defined contribution pension plan, the benefits a participant will receive depend solely on the amount contributed to the participant's account, the returns earned on investments of those contributions, and forfeitures of other participants' benefits that may be allocated to such participant's account. A description of the plan(s) including employee groups covered, the basis for determining contributions, and the nature and effects of significant matters affecting comparability of information for all periods presented.

+ References+ Details

Retirement Benefits (Details3) (USD $)	12 Months Ended
Retirement Benefits (Details3) (USD $)	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Description of Defined Contribution Pension and Other Postretirement Plans	We sponsor a contributory health care plan that provides hospitalization, medical and dental benefits to substantially all U.S. associates. We provide certain health care and life insurance benefits for retired associates. The principal plans cover associates in the U.S. and Canada who have met certain eligibility requirements. Our principal post-retirement benefit plans are primarily unfunded. Retiree medical benefits provided under our U.S. postretirement benefit plans were closed to new hires effective January 1, 2011. Life insurance benefits under the plans were frozen with respect to service, eligibility and amounts as of January 1, 2012 for active associates.
Health Care Benefits Incurred But Unreported Claims Liability	$ 4,500,000	$ 6,800,000
Towers Watson Us [Member]
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Description of Defined Contribution Pension and Other Postretirement Plans	Eligible Towers Watson U.S. associates hired on or after January 1, 2011 participate in a new savings plan design which provides for 100% match on the first 2% of pay and 50% match on the next 4% of pay; associates vest in the employer match upon two years of service. Associates hired prior to 2011 continued participation in their respective legacy plans until January 1, 2012 at which time the legacy plans were frozen to new contributions and the associates began participation in the new savings plan design. Under the legacy U.S. Watson Wyatt plan, associate contributions were matched at a rate of 50% of the first 6% up to $60,000 of associates’ eligible compensation. The legacy U.S. Towers Perrin plan provided a matching contribution of 100% of the first 5% of associate contributions.
Defined Contribution Plan Contributions By Employer	28,700,000	25,200,000	17,000,000
Towers Watson Uk [Member]
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Description of Defined Contribution Pension and Other Postretirement Plans	The Towers Watson U.K. pension plan has a money purchase feature to which we make core contributions plus additional contributions matching those of the participating associates up to a maximum rate. Contribution rates depend on the age of the participant and whether or not they arise from salary sacrifice arrangements through which the associate has elected to receive a pension contribution in lieu of additional salary.
Defined Contribution Plan Contributions By Employer	21,400,000	16,500,000	10,000,000
United States Pension Plans
Defined Benefit Plan [Line Items]
Contributions during the year	7,000,000	30,000,000
Estimated contributions in next fiscal year	50,000,000
Canada Pension Plans
Defined Benefit Plan [Line Items]
Contributions during the year	15,473,000	6,346,000
Estimated contributions in next fiscal year	27,661,000
Europe Pension Plans
Defined Benefit Plan [Line Items]
Contributions during the year	20,437,000	19,216,000
Estimated contributions in next fiscal year	$ 38,820,000