Segment Information Revenue by Major Customers, by Reporting Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue, Major Customer [Line Items]
Net revenues	$ 54,482	$ 58,583	$ 51,924	$ 45,159	$ 33,496	$ 31,420	$ 28,761	$ 26,351	$ 210,148	$ 120,028	$ 100,104
Sales
Revenue, Major Customer [Line Items]
Number of customers									2	2	2
Sales | Customer A
Revenue, Major Customer [Line Items]
Net revenues									43,500	20,400	11,200
Concentration risk (as a percent)									20.70%	17.00%	11.10%
Sales | Customer B
Revenue, Major Customer [Line Items]
Net revenues									$ 42,700	$ 12,700	$ 11,000
Concentration risk (as a percent)									20.30%	10.50%	11.00%