Unaudited Quarterly Financial Data Unaudited Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Net sales	$ 510,162	$ 416,471	$ 357,287	$ 292,826	$ 311,848	$ 358,314	$ 351,620	$ 289,716	$ 1,576,746	$ 1,311,498	$ 1,210,156
Gross profit	113,794	97,101	83,818	66,697	72,122	81,642	79,491	61,819	361,410	295,074	256,547
Net (loss) income	$ (7,442)	$ 4,047	$ 2,125	$ (3,561)	$ 3,950	$ 7,532	$ 84,224	$ (1,674)	$ (4,831)	$ 94,032	$ 21,655
Basic income (loss) per share
Net income (loss) per share (in dollars per share)	$ (0.16)	$ 0.10	$ 0.05	$ (0.09)	$ 0.10	$ 0.19	$ 2.17	$ (0.04)	$ (0.12)	$ 2.42	$ 0.57
Diluted income (loss) per share
Net income (loss) per share (in dollars per share)	$ (0.16)	$ 0.10	$ 0.05	$ (0.09)	$ 0.10	$ 0.19	$ 2.14	$ (0.04)	$ (0.12)	$ 2.39	$ 0.56