Restructuring Charges Restructuring Charges (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012 position	Sep. 30, 2014	Sep. 30, 2013
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated	160
Costs incurred and charged to expense		$ 3,805	$ 4,075
Asset Related and Other Costs
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense		0	1,184
Employee Separation Costs
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense		3,805	2,891
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance		756
Costs incurred and charged to expense, excluding non-cash charges		3,805
Cash payments		(3,626)
Accrued liability ending balance		$ 935