Commitments and Contingencies - Asbestos Claimant and Settlement (Details) (Asbestos [Member], USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2012 claimants	Dec. 31, 2011 claimants
Asbestos [Member]
Loss Contingencies [Line Items]
Number of pending claims at beginning of period	8,048	8,200
Number of pending claims filed during period	185	476
Number of pending claims dismissed during period	310	607
Number of pending claims settled during period	12	21
Average settlement amount per claim during period	$ 17,858	$ 14,300
Total defense costs during period	$ 1,460,000	$ 2,510,000