Benefits Plan - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit, defined contribution and employee stock ownership costs			$ 45,700,000	$ 34,600,000	$ 27,400,000
Targeted future ESOP allocations for Covered Compensation			3.00%
Employee Stock Ownership Plan (ESOP), Plan
Defined Benefit Plan Disclosure [Line Items]
Amendment to the DENTSPLY to redesign future distribution of allocations of Covered Compensation			3.00%
Contributions to defined contribution benefit plans			4,600,000	3,600,000	3,000,000
Defined Contribution Pension Plan 401k
Defined Benefit Plan Disclosure [Line Items]
Amendment to the DENTSPLY to redesign future distribution of allocations of Covered Compensation			3.00%
Contributions to defined contribution benefit plans	5,300,000	4,900,000	7,600,000	5,800,000	4,600,000
Other Defined Contribution Plans			13,900,000	8,100,000	6,700,000
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined contribution benefit plans			12,144,000	9,647,000
Minimum target allocation for plan asset of Fixed Income Securities			30.00%
Defined Benefit Plan Target Allocation Percentage Of Assets Fixed Income Securities Range Maximum			65.00%
Defined Benefit Plan Target Allocation Percentage Of Assets Real Estate Funds Range Minimum			0.00%
Defined Benefit Plan Target Allocation Percentage Of Assets Real Estate Funds Range Maximum			15.00%
Defined Benefit Plan Target Allocation Percentage Of Assets all other investment types Range Minimum			0.00%
Defined Benefit Plan Target Allocation Percentage Of Assets all other investment types Range Maximum			25.00%
Maximum target allocation for plan asset of Fixed Income Securities			30.00%
Defined Benefit Plan Target Allocation Percentage Of Assets Equity Range Maximum			65.00%
Defined benefit plan narrative description			The objective is to achieve a long-term rate of return in excess of 5% while at the same time mitigating the impact of investment risk associated with investment categories that are expected to yield greater than average returns.
Defined benefit plans that will be amortized from AOCI into net periodic benefit cost			5,000,000
Percentage of Total Plan Assets Categorized As Level One			80.00%
Expected contributions to defined benefit pension plans in 2012			7,700,000
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined contribution benefit plans			285,000	541,000
Defined benefit plans that will be amortized from AOCI into net periodic benefit cost			400,000
Postretirement Medical Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected contributions to defined benefit pension plans in 2012			$ 700,000