Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities
Net income (loss)	$ 5,853	$ (914)	$ (7,761)	$ 20,507	$ 5,509	$ 24,337	$ 15,003	$ (22,300)	$ (150,934)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	19,355	25,187	38,792	50,201	57,790	74,827	75,993	98,139	99,246
Stock-based compensation	4,108	4,584	7,997	9,454	10,879	13,306	14,089	17,860	18,850
Amortization of prepaid debt fees	390	404	1,579	808	1,851	1,212	2,128	1,612	1,657
Deferred taxes, net	(4,932)	(2,703)	1,885	(9,499)	14,744	(13,068)	1,488	(34,757)	(25,308)
Goodwill impairment	0	0	0	0	0	0	0	0	174,226
Restructuring, non-cash	(110)	0	(110)	0	1,018	0	976	5,172	1,259
Other adjustments, net	337	32	919	85	1,877	120	2,003	914	551
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	237	15,186	(8,641)	(14,540)	(14,193)	(1,768)	(9,009)	(15,119)	11,732
Inventories	(23,732)	(12,449)	(49,928)	(16,145)	(73,464)	(23,085)	(52,737)	7,208	(12,391)
Other current assets	(7,888)	5,838	(6,254)	(3,768)	(998)	(5,154)	12,512	(10,947)	(9,950)
Other long-term assets	(3,081)	(9,446)	(3,185)	(10,166)	(2,529)	(15,766)	(3,721)	(12,540)	(2,298)
Accounts payables, other current liabilities, and taxes payable	3,760	26,804	23,965	12,797	(11,119)	20,105	(7,060)	56,158	(4,466)
Wages and benefits payable	(9,913)	(2,092)	(5,846)	1,356	3,787	3,839	(10,866)	7,502	(1,822)
Unearned revenue	14,582	19,217	10,649	25,999	6,536	35,704	11,943	30,584	8,744
Warranty	2,384	(342)	23,046	(3,881)	20,207	(4,560)	20,161	(7,297)	(6,546)
Other operating, net	(5,305)	(2,545)	(9,540)	3,983	(1,741)	6,489	447	10,784	2,871
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	(3,955)	66,761	17,567	67,191	20,154	116,538	73,350	132,973	105,421
Investing activities
Acquisitions of property, plant, and equipment	(9,472)	(8,564)	(20,992)	(19,403)	(33,324)	(32,060)	(43,918)	(44,495)	(60,020)
Payments to Acquire Businesses, Net of Cash Acquired	0	0	0	0	(5,754)	0	(5,754)	0	(860)
Other investing, net	(118)	167	693	56	545	(193)	721	2,999	4,109
Net cash used in investing activities	(9,590)	(8,397)	(20,299)	(19,347)	(38,533)	(32,253)	(48,951)	(41,496)	(56,771)
Financing activities
Proceeds from borrowings	63,000	0	74,183	0	89,709	0	113,467	47,657	35,000
Payments on debt	(22,373)	(30,625)	(22,373)	(51,250)	(30,186)	(68,750)	(62,998)	(102,438)	(73,750)
Issuance of common stock	451	310	1,864	1,530	2,229	2,324	2,663	3,647	5,299
Repurchase of common stock	(16,341)	(2,948)	(23,185)	(7,164)	(35,278)	(15,324)	(38,283)	(39,665)	(26,977)
Other financing, net	1,186	(2,244)	(3,942)	1,204	1,881	2,395	(7,109)	(1,078)	2,990
Net cash provided by (used in) financing activities	25,923	(35,507)	26,547	(55,680)	28,355	(79,355)	7,740	(91,877)	(57,438)
Effect of foreign exchange rate changes on cash and cash equivalents	(6,665)	(1,335)	(7,372)	(2,189)	(12,889)	(7,260)	(13,492)	(12,034)	(2,818)
Increase (decrease) in cash and cash equivalents	5,713	21,522	16,443	(10,025)	(2,913)	(2,330)	18,647	(12,434)	(11,606)
Cash and cash equivalents at beginning of period	112,371	124,805	112,371	124,805	112,371	124,805	112,371	124,805	136,411
Cash and cash equivalents at end of period	118,084	146,327	128,814	114,780	109,458	122,475	131,018	112,371	124,805
Supplemental disclosure of cash flow information:
Income taxes, net	19,245	(891)	21,233	3,502	22,578	8,528	29,189	18,222	18,659
Interest, net of amounts capitalized	$ 2,265	$ 2,460	$ 4,998	$ 4,911	$ 7,549	$ 7,536	$ 10,198	$ 9,912	$ 9,026