Geographic Areas - Schedule of Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Products	$ 189,914	$ 188,859	$ 361,915	$ 349,344
Services	40,401	33,172	72,473	65,842
Intercompany	13,350	15,633	25,184	28,306
Eliminations	(13,350)	(15,633)	(25,184)	(28,306)
Total Revenues	230,315	222,031	434,388	415,186
Total Long-Lived Assets	327,040		327,040		315,799
Income before income taxes	69,215	56,376	127,858	108,655
Total Assets	1,448,560		1,448,560		1,394,612
Eliminations [Member]
Segment Reporting Information [Line Items]
Income before income taxes	1,525	2,928	3,206	3,562
Total Long-Lived Assets Eliminations	(2,926)		(2,926)		(2,927)
Total Assets Eliminations	(33,656)		(33,656)		(17,530)
Western Hemisphere [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Products	115,953	95,871	210,342	195,600
Services	18,381	18,567	35,281	34,196
Intercompany	9,063	10,891	19,355	23,278
Total Revenues	143,397	125,329	264,978	253,074
Total Long-Lived Assets	224,188		224,188		216,104
Income before income taxes	36,010	19,199	72,170	44,145
Total Assets	785,759		785,759		803,069
Eastern Hemisphere [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Products	43,814	60,647	97,737	98,480
Services	16,514	10,400	27,991	22,567
Intercompany	3,325	596	3,499	751
Total Revenues	63,653	71,643	129,227	121,798
Total Long-Lived Assets	48,185		48,185		43,430
Income before income taxes	15,827	21,116	31,174	38,124
Total Assets	364,355		364,355		316,473
Asia-Pacific [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Products	30,147	32,341	53,836	55,264
Services	5,506	4,205	9,201	9,079
Intercompany	962	4,146	2,330	4,277
Total Revenues	36,615	40,692	65,367	68,620
Total Long-Lived Assets	57,593		57,593		59,192
Income before income taxes	15,853	13,133	21,308	22,824
Total Assets	$ 332,102		$ 332,102		$ 292,600