Restructuring Charges (Details) (USD $)	3 Months Ended	9 Months Ended	2 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	11 Months Ended	3 Months Ended	9 Months Ended	11 Months Ended	3 Months Ended	9 Months Ended	11 Months Ended	3 Months Ended	9 Months Ended	11 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013 2013 Plan	Sep. 30, 2013 2013 Plan	Sep. 30, 2013 2013 Plan item	Sep. 30, 2013 2013 Plan North America	Sep. 30, 2013 2013 Plan North America	Sep. 30, 2013 2013 Plan International	Sep. 30, 2013 2013 Plan International	Sep. 30, 2013 2013 Plan Other	Sep. 30, 2013 2013 Plan Other	Sep. 30, 2013 2013 Plan Corporate	Sep. 30, 2013 2013 Plan Corporate	Sep. 30, 2013 2012 Plan	Sep. 30, 2013 2012 Plan	Sep. 30, 2013 2012 Plan	Sep. 30, 2013 2012 Plan North America	Sep. 30, 2013 2012 Plan North America	Sep. 30, 2013 2012 Plan North America	Sep. 30, 2013 2012 Plan International	Sep. 30, 2013 2012 Plan International	Sep. 30, 2013 2012 Plan International	Sep. 30, 2013 2012 Plan Corporate	Sep. 30, 2013 2012 Plan Corporate	Sep. 30, 2013 2012 Plan Corporate	Sep. 30, 2013 2012 Plan Employee Severance and Termination	Sep. 30, 2013 2012 Plan Employee Severance and Termination International	Sep. 30, 2013 2012 Plan Office Closures item
Restructuring Charges
Expected number of employees to be impacted by the restructuring					220
Total restructuring charges															$ 11,000,000												$ 7,000,000	$ 4,000,000
Non-cash items related to stock compensation and lease															1,000,000
Number of offices closed																												17
Changes in restructuring liabilities, recorded in other accrued expenses
Restructuring liability at the beginning of period															5,088,000											3,556,000		1,532,000
Restructuring charges	14,000,000	14,953,000		11,786,000		660,000		10,484,000		54,000		588,000		2,214,000	3,167,000		262,000	158,000		161,000	1,091,000		1,791,000	1,918,000		411,000		2,756,000
Non-cash items				(137,000)											510,000													510,000
Cash paid				(1,865,000)											(5,189,000)											(3,746,000)		(1,443,000)
Foreign exchange rate changes				187,000											(62,000)											(75,000)		13,000
Restructuring liability at the end of period			9,971,000	9,971,000	9,971,000									3,514,000	3,514,000	3,514,000										146,000		3,368,000
Total Anticipated Charges					13,000,000		700,000		11,645,000		55,000		600,000
Restructuring charges, incurred to date			$ 12,000,000													$ 11,148,000			$ 1,622,000			$ 6,865,000			$ 2,661,000