Original and Further Restatement of the Consolidated Financial Statements - Effects of Further Restatement on Consolidated Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 28,919	$ 28,924	$ 26,369	$ 30,767
Restricted cash	45,248	23,761
Trade accounts receivable, less allowances of $9111 at December 31, 2013	63,322	70,811
Inventories	70,902	72,678
Deferred income taxes	40,402	39,999
Prepaid expenses and other current assets	43,886	28,933
Total current assets	292,679	265,106
Property, plant and equipment, net	51,082	54,372
Patents and other intangible assets, net	8,075	9,046
Goodwill	53,565	53,565
Deferred income taxes	22,762	22,394
Other long-term assets	5,834	7,492
Total assets	433,997	411,975
Current liabilities:
Trade accounts payable	15,712	20,674
Other current liabilities	67,382	49,676
Total current liabilities	83,094	70,350
Long-term debt	20,000	20,000
Deferred income taxes	13,325	13,026
Other long-term liabilities	12,367	12,736
Total liabilities	128,786	116,112
Contingencies (Note 16)
Shareholders' equity:
Common shares $0.10 par value; 50,000,000 shares authorized; 18,102,335 issued and outstanding as of December 31, 2013	1,854	1,810
Additional paid-in capital	228,502	216,653
Retained earnings	70,706	73,897
Accumulated other comprehensive income	4,149	3,503
Total shareholders' equity	305,211	295,863
Total liabilities and shareholders' equity	433,997	411,975
Previously Reported [Member]
Current assets:
Cash and cash equivalents		30,486	27,370	31,055
Restricted cash		23,761
Trade accounts receivable, less allowances of $9111 at December 31, 2013		75,567
Inventories		90,577
Deferred income taxes		33,947
Prepaid expenses and other current assets		25,906
Total current assets		280,244
Property, plant and equipment, net		54,606
Patents and other intangible assets, net		9,046
Goodwill		53,565
Deferred income taxes		18,336
Other long-term assets		7,385
Total assets		423,182
Current liabilities:
Trade accounts payable		20,674
Other current liabilities		46,146
Total current liabilities		66,820
Long-term debt		20,000
Deferred income taxes		13,132
Other long-term liabilities		12,736
Total liabilities		112,688
Contingencies (Note 16)
Shareholders' equity:
Common shares $0.10 par value; 50,000,000 shares authorized; 18,102,335 issued and outstanding as of December 31, 2013		1,810
Additional paid-in capital		216,653
Retained earnings		89,332
Accumulated other comprehensive income		2,699
Total shareholders' equity		310,494
Total liabilities and shareholders' equity		423,182
Restatement Adjustments [Member]
Current assets:
Cash and cash equivalents		(1,562)	(1,001)	(288)
Restricted cash
Trade accounts receivable, less allowances of $9111 at December 31, 2013		(4,756)
Inventories		(17,899)
Deferred income taxes		6,052
Prepaid expenses and other current assets		3,027
Total current assets		(15,138)
Property, plant and equipment, net		(234)
Patents and other intangible assets, net
Goodwill
Deferred income taxes		4,058
Other long-term assets		107
Total assets		(11,207)
Current liabilities:
Trade accounts payable
Other current liabilities		3,530
Total current liabilities		3,530
Long-term debt
Deferred income taxes		(106)
Other long-term liabilities
Total liabilities		3,424
Contingencies (Note 16)
Shareholders' equity:
Common shares $0.10 par value; 50,000,000 shares authorized; 18,102,335 issued and outstanding as of December 31, 2013
Additional paid-in capital
Retained earnings		(15,435)
Accumulated other comprehensive income		804
Total shareholders' equity		(14,631)
Total liabilities and shareholders' equity		$ (11,207)