Property, Equipment and Building Improvements (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended		3 Months Ended
	Aug. 29, 2012	Mar. 14, 2008	Mar. 31, 2013 item
Plant and Equipment disclosures
Lease agreement term		7 years 6 months
Lease expiration period from the commencement date	15 years
Total lease payment			$ 40.7
Number of lease renewal options			2
Maximum
Plant and Equipment disclosures
Lease, renewal option			10 years
Lease Renewal Term One | Minimum
Plant and Equipment disclosures
Lease, renewal option			3 years
Lease Renewal Term One | Maximum
Plant and Equipment disclosures
Lease, renewal option			7 years
Lease Renewal Term Two | Maximum
Plant and Equipment disclosures
Lease term as compared to first renewal term			10 years
Building
Plant and Equipment disclosures
Property, plant and equipment, useful life			30 years
Computers and Equipment | Minimum
Plant and Equipment disclosures
Property, plant and equipment, useful life			3 years
Computers and Equipment | Maximum
Plant and Equipment disclosures
Property, plant and equipment, useful life			5 years
Building Improvements | Maximum
Plant and Equipment disclosures
Property, plant and equipment, useful life			15 years