Summary of Significant Accounting Policies Narrative (Details) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended					12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2011	Jan. 31, 2011	Sep. 30, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounting Policies [Line Items]
Other-than-temporary impairment loss								$ 500
Allowance for doubtful accounts and cash discounts	577					577	881
Current restricted assets	2,469					2,469	1,474
Long-term restricted assets	9,792					9,792	9,626
Indefinite life intangible assets	107,511					107,511	107,511
Shares paid for exercise of options and tax withholding for share based compensation (in shares)				384,946
Shares paid for exercise of other than options and tax withholding for share based compensation (in shares)	162,397	76,155	67,275		57,265
Exercise of employee stock options, net of shares delivered to pay exercise price (in shares)				448,960		16,079	531,321	128,189
Shipping and handling fees and costs						5,474	5,684	5,323
Advertising costs						4,266	3,099	2,970
Fair market value of embedded derivatives at the midpoint of the inputs	172,128					172,128	133,500
Minimum [Member]
Accounting Policies [Line Items]
Inventory classification of current asset, range						1 year
Intangible asset useful life						10 years
Unrecognized tax benefits, recognition of tax positions, likelihood of being realized upon settlement						50.00%
Fair market value of embedded derivatives at the midpoint of the inputs	169,424					169,424	130,917
Maximum [Member]
Accounting Policies [Line Items]
Cash equivalent, maturity period						90 days
Marketable securities, ownership interest						20.00%
Intangible asset useful life						12 years
Fair market value of embedded derivatives at the midpoint of the inputs	$ 174,909					$ 174,909	$ 136,182