Debt and Operating Leases (Details) (USD $)	12 Months Ended				12 Months Ended						1 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Nov. 10, 2010	Dec. 31, 2012 Chicago, Illinois [Member] sqft	Dec. 31, 2012 Daytona Beach, Florida [Member] sqft	Dec. 31, 2012 Hartland, Wisconsin [Member] sqft	Dec. 31, 2012 Mississauga, Ontario [Member] sqft	Dec. 31, 2012 Morrisville, North Carolina [Member] sqft	Dec. 31, 2012 Lease Line Credit Facility [Member]	Jun. 30, 2011 Senior Secured Notes [Member]	Apr. 30, 2010 Senior Secured Notes [Member]	Dec. 31, 2012 Senior Secured Notes [Member]	Dec. 31, 2011 Senior Secured Notes [Member]	Dec. 31, 2010 Senior Secured Notes [Member]
Debt Instrument [Line Items]
Principal amount of notes issued											$ 52,000,000	$ 200,000,000
Notes issued specified as percentage of principal amount (in hundredths)											103.00%	97.266%
Interest rate of notes (in hundredths)												11.75%
Maturity date of notes													May 01, 2015
Issuance cost of notes												9,015,000
Capitalized consent fees											1,528,000
Consent fees not capitalized											1,686,000
Interest expense													32,334,000	29,135,000	17,308,000
Interest paid	29,654,000	25,723,000	11,956,000										29,610,000	25,723,000	11,946,000
Amortization of notes issuance costs													2,049,000	1,659,000	899,000
Amortization of net debt discount													675,000	733,000	546,000
Unamortized discount on notes			5,468,000										1,954,000	2,629,000
Repayments of assumed debt		4,591,000
Redemption price specified as percentage of principal amount on or prior to May 1, 2013 (in hundredths)													100.00%
Redemption price specified as percentage of principal amount during twelve month period commencing May 1, 2013 (in hundredths)													105.875%
Redemption price specified as percentage of principal amount after May 1, 2014 (in hundredths)													100.00%
Maximum percentage of notes redeemed at par in specified period (in hundredths)													35.00%
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity										15,000,000
Interest rate (in hundredths)										7.40%
Line of credit, unused borrowing capacity										14,100,000
Line of credit, amount outstanding										900,000
Operating Leased Assets [Line Items]
Number of largest operating leases	5
Non-cancelable operating leases [Abstract]
Square Footage					33,000	36,000	81,000	24,000	17,000
Annual Lease Payments					612,000	332,000	694,000	615,000	258,000
End of Term					December 2013	December 2013	November 2025	February 2020	September 2016
Sale leaseback transaction date			2010-11-10
Proceeds from sale leaseback transaction			6,124,000
Deferred gain on sale leaseback transaction				227,000
Amortization period for deferred gain on sale leaseback transaction			15 years
Total rent expense	3,351,000	3,443,000	2,031,000
Future minimum lease payments under all non-cancelable operating leases [Abstract]
2013	3,186,000
2014	1,724,000
2015	1,756,000
2016	1,585,000
2017	1,350,000
Thereafter	6,915,000
Total minimum lease payments	16,516,000
Operating leases subleases revenue receivable current	227,000
Operating leases subleases revenue receivable in two years	$ 76,000