Selected Quarterly Financial Data (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Selected Quarterly Financial Information [Abstract]
Net sales	$ 210,993	$ 224,510	$ 214,379	$ 176,964	$ 163,287	$ 166,617	$ 159,239	$ 144,663	$ 826,846	$ 633,806	$ 635,251
Gross profit	60,801	69,559	61,293	46,183	43,247	43,605	41,028	33,706	237,836	161,586	193,697
Net income attributable to common stockholders	$ 6,204	$ 13,619	$ 8,635	$ (1,926)	$ 4,075	$ 8,553	$ 6,653	$ 4,871	$ 26,532	$ 24,152	$ 50,737
Earnings per share attributable to common shareholders
Basic	$ 0.13	$ 0.29	$ 0.19	$ (0.04)	$ 0.09	$ 0.19	$ 0.15	$ 0.11	$ 0.57	$ 0.53	$ 1.12
Diluted	$ 0.13	$ 0.28	$ 0.18	$ (0.04)	$ 0.09	$ 0.18	$ 0.14	$ 0.10	$ 0.56	$ 0.51	$ 1.09