Debt - Debt (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total debt		$ 317,013	$ 331,354	[1]
Less current maturities		28,154	18,806	[1]
Long-term debt	[2]	288,859	312,548	[1]
Unsecured private placement 3.95% note [Member]
Debt Instrument [Line Items]
Total debt		$ 99,618	$ 99,617	[1]
Debt instrument interest rate percentage		3.95%	3.95%
Unsecured private placement 3.95% note [Member] | Minimum [Member]
Debt Instrument [Line Items]
Maturity Dates		2021	2021
Unsecured private placement 3.95% note [Member] | Maximum [Member]
Debt Instrument [Line Items]
Maturity Dates		2027	2027
Unsecured private placement 3.86% note [Member]
Debt Instrument [Line Items]
Total debt		$ 99,610	$ 99,560	[1]
Debt instrument interest rate percentage		3.86%	3.86%
Unsecured private placement 3.86% note [Member] | Minimum [Member]
Debt Instrument [Line Items]
Maturity Dates		2019	2019
Unsecured private placement 3.86% note [Member] | Maximum [Member]
Debt Instrument [Line Items]
Maturity Dates		2025	2025
Unsecured private placement 4.86% note [Member]
Debt Instrument [Line Items]
Total debt		$ 64,775	$ 64,740	[1]
Debt instrument interest rate percentage		4.86%	4.86%
Unsecured private placement 4.86% note [Member] | Minimum [Member]
Debt Instrument [Line Items]
Maturity Dates		2017	2017
Unsecured private placement 4.86% note [Member] | Maximum [Member]
Debt Instrument [Line Items]
Maturity Dates		2023	2023
Unsecured private placement 5.88% note [Member]
Debt Instrument [Line Items]
Total debt		$ 34,170	$ 39,860	[1]
Debt instrument interest rate percentage		5.88%	5.88%
Unsecured private placement 5.88% note [Member] | Minimum [Member]
Debt Instrument [Line Items]
Maturity Dates		2017	2017
Unsecured private placement 5.88% note [Member] | Maximum [Member]
Debt Instrument [Line Items]
Maturity Dates		2022	2022
Unsecured private placement 5.69% note [Member]
Debt Instrument [Line Items]
Total debt		$ 11,400	$ 17,096	[1]
Debt instrument interest rate percentage		5.69%	5.69%
Unsecured private placement 5.69% note [Member] | Minimum [Member]
Debt Instrument [Line Items]
Maturity Dates		2017	2017
Unsecured private placement 5.69% note [Member] | Maximum [Member]
Debt Instrument [Line Items]
Maturity Dates		2018	2018
Debt of foreign subsidiaries Unsecured bank debt, foreign currency [Member]
Debt Instrument [Line Items]
Total debt		$ 432	$ 4,810	[1]
Maturity Dates		2017	2017
Debt of foreign subsidiaries Unsecured bank term loan, foreign currency [Member]
Debt Instrument [Line Items]
Total debt	[1]		$ 3,724
Maturity Dates		2021	2021
Debt of foreign subsidiaries Secured bank debt, foreign currency [Member]
Debt Instrument [Line Items]
Total debt		$ 7,008	$ 1,947	[1]
Maturity Dates		2017	2017

[1] Certain balances have been reclassified from those originally presented at December 31, 2015, due to the Company’s January 1, 2016, adoption of the new U.S. GAAP guidance regarding the classification of debt issuance costs. See Note 1 for additional information regarding ASU No. 2015-3.

[2] The 2015 amounts have been changed from the amounts originally reported at December 31, 2015, due to the Company’s January 1, 2016, adoption of the new U.S. accounting guidance regarding the classification of debt issuance costs. See Note 1 to the consolidated financial statements for additional information regarding Accounting Standards Update No. 2015-3.