Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounts receivable allowances
Changes in valuation and qualifying accounts
Balance at Beginning of Period	$ 1,771	$ 1,822	$ 1,148
Additions	37,098	26,517	14,074
Deductions Charged to Reserves	(36,186)	(26,568)	(13,400)
Balance at End of Period	2,683	1,771	1,822
Rebates, fees and returns reserves
Changes in valuation and qualifying accounts
Balance at Beginning of Period	3,448	5,943	10,015
Additions	11,820	6,729	9,864
Deductions Charged to Reserves	(10,469)	(9,224)	(13,936)
Balance at End of Period	$ 4,799	$ 3,448	$ 5,943