Segments (Schedule of net sales, adjusted EBITDA and certain other measures by reportable segment) (Details) - USD ($) $ 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
Segment Reporting Information [Line Items]
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
Depreciation & amortization									24,589	15,457	13,767
Total assets	1,376,008				588,512				1,376,008	588,512	468,272
Operating segments [Member] | Geographic divisions [Member]
Segment Reporting Information [Line Items]
Net sales									1,576,746	1,311,498	1,210,156
Gross profit									361,410	295,074	256,547
Depreciation & amortization									23,726	14,906	13,156
Adjusted EBITDA									122,914	98,933	84,457
Total assets	1,305,545				487,027				1,305,545	487,027	446,716
Other reconciling items [Member] | Other reconciling items [Member]
Segment Reporting Information [Line Items]
Net sales									0	0	0
Gross profit									0	0	0
Depreciation & amortization									863	551	611
Adjusted EBITDA									(36,872)	(21,664)	(19,706)
Total assets	$ 70,463				$ 101,485				$ 70,463	$ 101,485	$ 21,556