Restructuring Costs (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restructuring liability [Roll Forward]
Balance, beginning of period	$ 1,400,000
Additional provisions (reversals)	0
Cash expenditures	(1,100,000)	(2,500,000)
Balance, end of period	300,000	1,400,000
Restructuring and other costs	0	470,000	865,000
Employee Severance and Other Employee Benefits [Member]
Restructuring liability [Roll Forward]
Balance, beginning of period	600,000
Additional provisions (reversals)	0
Cash expenditures	(500,000)
Balance, end of period	100,000
Contract Termination Costs [Member]
Restructuring liability [Roll Forward]
Balance, beginning of period	800,000
Additional provisions (reversals)	0
Cash expenditures	(600,000)
Balance, end of period	$ 200,000