Restructuring Charges (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 position	Dec. 31, 2012	Dec. 31, 2011
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated	160
Restructuring and other charges	$ 5,765,000	$ 15,225,000	$ 8,650,000
Costs incurred and charged to expense	5,765,000	15,225,000	8,650,000
Unpaid Asset Related Restructuring Costs	300,000
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	2,431,000
Costs incurred and charged to expense for the year ended December 31, 2013	3,961,000
Cash payments	(5,636,000)
Accrued liability ending balance	756,000	2,431,000
Employee Separation Costs
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	3,961,000	9,052,000	7,739,000
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	731,000
Costs incurred and charged to expense for the year ended December 31, 2013	3,961,000
Cash payments	(3,936,000)
Accrued liability ending balance	756,000	731,000
Contract Assignment Costs
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	0	3,629,000	0
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	1,700,000
Costs incurred and charged to expense for the year ended December 31, 2013	0
Cash payments	(1,700,000)
Accrued liability ending balance	0	1,700,000
Asset Related and Other Costs
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	$ 1,804,000	$ 2,544,000	$ 911,000