Restructuring Charges Restructuring Charges (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 position	Mar. 31, 2012
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated	160
Restructuring and other charges	$ 1,382,000	$ 1,609,000
Employee separation	1,400,000
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	2,431,000
Costs incurred and charged to expense, excluding non-cash charges	1,382,000
Cash payments	(1,199,000)
Accrued liability ending balance	2,614,000
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	1,382,000	1,609,000
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	731,000
Costs incurred and charged to expense, excluding non-cash charges	1,382,000
Cash payments	(1,199,000)
Accrued liability ending balance	914,000
Contract Termination [Member]
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	1,700,000
Costs incurred and charged to expense, excluding non-cash charges	0
Cash payments	0
Accrued liability ending balance	$ 1,700,000