Quarterly Results (Unaudited) Quarterly Revised Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)	$ 13,270	$ (13,614)	$ 5,853	$ 3,830	$ 21,421	$ (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
Increase (Decrease) in Deferred Income Taxes			(4,932)			(2,703)	1,885	(9,499)	14,744	(13,068)	1,488	(34,757)	(25,308)
Goodwill, Impairment Loss	0	0	0	0	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:
Increase (Decrease) in Accounts Receivable			237			15,186	(8,641)	(14,540)	(14,193)	(1,768)	(9,009)	(15,119)	11,732
Increase (Decrease) in 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)
Increase (Decrease) in Other Noncurrent 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
Payments to Acquire 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)
Payments for (Proceeds from) Other Investing Activities			(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
Repayments of Long-term 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	109,458	128,814	118,084	122,475	114,780	146,327	128,814	114,780	109,458	122,475	131,018	112,371	124,805	$ 136,411
Non-cash transactions:
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
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)	13,325	(13,466)	5,365	7,553	19,844	(118)	(8,101)	19,726	5,224	27,279		(21,550)	(144,590)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization			19,339			25,592	38,760	50,606	58,514	75,233		98,463	98,845
Stock-based compensation			4,108			4,584	7,997	9,454	10,879	12,703		17,860	18,850
Amortization of prepaid debt fees			390			404	1,579	808	1,851	1,212		1,612	1,657
Increase (Decrease) in Deferred Income Taxes			(4,790)			(3,915)	1,901	(8,046)	14,926	(9,787)		(31,542)	(26,757)
Goodwill, Impairment Loss	0	0	0	0	0	977	0	977	0	977		977	173,249
Restructuring, non-cash			267			0	267	0	1,395	0		5,220	1,259
Other adjustments, net			337			32	919	85	1,877	120		914	551
Changes in operating assets and liabilities, net of acquisitions:
Increase (Decrease) in Accounts Receivable			2,028			15,392	(6,849)	(14,712)	(12,401)	(1,576)		(16,789)	13,652
Increase (Decrease) in Inventories			(23,480)			(15,827)	(49,677)	(16,801)	(73,212)	(23,986)		6,021	(10,861)
Other current assets			(9,395)			(1,547)	(9,043)	(9,103)	(4,696)	(5,298)		(9,447)	(4,143)
Increase (Decrease) in Other Noncurrent Assets			(54)			892	406	312	605	(1,396)		1,582	1,093
Accounts payables, other current liabilities, and taxes payable			3,774			25,303	23,990	12,360	(11,666)	19,669		55,924	(7,702)
Wages and benefits payable			(10,343)			272	(6,276)	4,473	4,110	6,717		10,334	(1,995)
Unearned revenue			11,032			16,441	7,807	16,560	4,128	11,800		9,240	(3,274)
Warranty			2,457			675	23,119	(2,864)	20,280	(3,544)		(6,364)	(7,552)
Other operating, net			(4,990)			(2,396)	(9,232)	3,356	(1,660)	6,415		10,518	3,139
Net Cash Provided by (Used in) Operating Activities, Continuing Operations			(3,955)			66,761	17,567	67,191	20,154	116,538		132,973	105,421
Investing activities
Payments to Acquire Property, Plant, and Equipment			(9,472)			(8,564)	(20,992)	(19,403)	(33,324)	(32,060)		(44,495)	(60,020)
Payments to Acquire Businesses, Net of Cash Acquired			0			0	0	0	(5,754)	0		0	(860)
Payments for (Proceeds from) Other Investing Activities			(118)			167	693	56	545	(193)		2,999	4,109
Net cash used in investing activities			(9,590)			(8,397)	(20,299)	(19,347)	(38,533)	(32,253)		(41,496)	(56,771)
Financing activities
Proceeds from borrowings			63,000			0	74,183	0	89,709	0		47,657	35,000
Repayments of Long-term Debt			(22,373)			(30,625)	(22,373)	(51,250)	(30,186)	(68,750)		(102,438)	(73,750)
Issuance of common stock			451			310	1,864	1,530	2,229	2,324		3,647	5,299
Repurchase of common stock			(16,341)			(2,948)	(23,185)	(7,164)	(35,278)	(15,324)		(39,665)	(26,977)
Other financing, net			1,186			(2,244)	(3,942)	1,204	1,881	2,395		(1,078)	2,990
Net cash provided by (used in) financing activities			25,923			(35,507)	26,547	(55,680)	28,355	(79,355)		(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)		(12,034)	(2,818)
Increase (decrease) in cash and cash equivalents			5,713			21,522	16,443	(10,025)	(2,913)	(2,330)		(12,434)	(11,606)
Cash and cash equivalents	109,458	128,814	118,084	122,475	114,780	146,327	128,814	114,780	109,458	122,475		112,371	124,805	136,411
Non-cash transactions:
Income taxes, net			19,245			(891)	21,233	3,502	22,578	8,528		18,222	18,659
Interest, net of amounts capitalized			2,265			2,460	4,998	4,911	7,549	7,536		9,912	9,026
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)	(55)	(148)	488	(3,723)	1,577	(796)	340	781	285	(2,942)		(750)	(6,344)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization			16			(405)	32	(405)	(724)	(406)		(324)	401
Stock-based compensation			0			0	0	0	0	603		0	0
Amortization of prepaid debt fees			0			0	0	0	0	0		0	0
Increase (Decrease) in Deferred Income Taxes			(142)			1,212	(16)	(1,453)	(182)	(3,281)		(3,215)	1,449
Goodwill, Impairment Loss	0	0	0	0	0	(977)	0	(977)	0	(977)		(977)	977
Restructuring, non-cash			(377)			0	(377)	0	(377)	0		(48)	0
Other adjustments, net			0			0	0	0	0	0		0	0
Changes in operating assets and liabilities, net of acquisitions:
Increase (Decrease) in Accounts Receivable			(1,791)			(206)	(1,792)	172	(1,792)	(192)		1,670	(1,920)
Increase (Decrease) in Inventories			(252)			3,378	(251)	656	(252)	901		1,187	(1,530)
Other current assets			1,507			7,385	2,789	5,335	3,698	144		(1,500)	(5,807)
Increase (Decrease) in Other Noncurrent Assets			(3,027)			(10,338)	(3,591)	(10,478)	(3,134)	(14,370)		(14,122)	(3,391)
Accounts payables, other current liabilities, and taxes payable			(14)			1,501	(25)	437	547	436		234	3,236
Wages and benefits payable			430			(2,364)	430	(3,117)	(323)	(2,878)		(2,832)	173
Unearned revenue			3,550			2,776	2,842	9,439	2,408	23,904		21,344	12,018
Warranty			(73)			(1,017)	(73)	(1,017)	(73)	(1,016)		(933)	1,006
Other operating, net			(315)			(149)	(308)	627	(81)	74		266	(268)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations			0			0	0	0	0	0		0	0
Investing activities
Payments to Acquire Property, Plant, and Equipment			0			0	0	0	0	0		0	0
Payments to Acquire Businesses, Net of Cash Acquired			0			0	0	0	0	0		0	0
Payments for (Proceeds from) Other Investing Activities			0			0	0	0	0	0		0	0
Net cash used in investing activities			0			0	0	0	0	0		0	0
Financing activities
Proceeds from borrowings			0			0	0	0	0	0		0	0
Repayments of Long-term Debt			0			0	0	0	0	0		0	0
Issuance of common stock			0			0	0	0	0	0		0	0
Repurchase of common stock			0			0	0	0	0	0		0	0
Other financing, net			0			0	0	0	0	0		0	0
Net cash provided by (used in) financing activities			0			0	0	0	0	0		0	0
Effect of foreign exchange rate changes on cash and cash equivalents			0			0	0	0	0	0		0	0
Increase (decrease) in cash and cash equivalents			0			0	0	0	0	0		0	0
Cash and cash equivalents	$ 0	$ 0	0	$ 0	$ 0	0	0	0	0	0		0	0	$ 0
Non-cash transactions:
Income taxes, net			0			0	0	0	0	0		0	0
Interest, net of amounts capitalized			$ 0			$ 0	$ 0	$ 0	$ 0	$ 0		$ 0	$ 0