Summary of Significant Accounting Policies (PPE and Revenue) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment
Impairment of long-lived assets	$ 0	$ 0	$ 0
Revenue Recognition
Period for sales return	6 months
Allowance for sales returns	$ 3,900,000	3,900,000
Shipping and handling charges	1,000,000	600,000	1,100,000
Accounts Receivable and Allowance for Doubtful Accounts
Allowance for doubtful accounts	900,000	400,000
Inventories and Cost of Goods Sold
Tax expense (or benefit)	(17,000)	61,000	0
Advertising
Advertising costs	1,800,000	600,000	$ 1,000,000
Breast Products
Inventories and Cost of Goods Sold
Inventory held on consignment at doctors' offices, clinics, and hospitals	$ 1,600,000	$ 2,000,000
Minimum
Property, Plant and Equipment
Estimated useful life of asset	3 years
Inventories and Cost of Goods Sold
Percentage of largest amount of tax benefit of settled uncertain tax position	50.00%
Maximum
Property, Plant and Equipment
Estimated useful life of asset	5 years