Commitments And Contingencies (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Feb. 28, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010 claim
Restructuring Cost and Reserve [Line Items]
Length of operating lease	10 years
Aggregate minimum lease payments	$ 4,400,000
Rent expense		5,600,000	5,400,000	5,700,000
Percentage of weighted average cost of capital		14.90%	14.90%
Number of claims dismissed				7
Severance and acceleration of equity awards contract obligations		1,500,000
Future contractual obligations to be recorded in first and second quarter of 2013		1,800,000
Savings in general and administrative costs		2,000,000
Selling, general and administrative expenses		109,071,000	91,173,000	80,742,000
Severance And Relocation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Selling, general and administrative expenses		$ 200,000	$ 100,000	$ 1,700,000