Financing Agreements - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended								0 Months Ended							0 Months Ended			6 Months Ended		0 Months Ended		0 Months Ended						0 Months Ended						0 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Aug. 31, 2009 Amended and Restated Credit Agreement	Mar. 22, 2012 Second Amended Restated Credit Agreement	Mar. 22, 2012 Second Amended Restated Credit Agreement Minimum	Mar. 22, 2012 Second Amended Restated Credit Agreement Maximum	Jun. 30, 2014 London Interbank Offered Rate (LIBOR)	Mar. 22, 2012 London Interbank Offered Rate (LIBOR) Second Amended Restated Credit Agreement	Mar. 22, 2012 London Interbank Offered Rate (LIBOR) Second Amended Restated Credit Agreement Minimum Scenario 1	Mar. 22, 2012 London Interbank Offered Rate (LIBOR) Second Amended Restated Credit Agreement Minimum Scenario 2	Mar. 22, 2012 London Interbank Offered Rate (LIBOR) Second Amended Restated Credit Agreement Maximum Scenario 1	Mar. 22, 2012 London Interbank Offered Rate (LIBOR) Second Amended Restated Credit Agreement Maximum Scenario 2	Jun. 30, 2014 Prime Lending Rate	Jun. 30, 2014 Federal Funds Rate	Mar. 22, 2012 Federal Funds Rate Second Amended Restated Credit Agreement	Jun. 30, 2014 Senior Unsecured Revolving Credit Facility	Dec. 31, 2007 Senior Unsecured Revolving Credit Facility	Jun. 30, 2014 Senior Unsecured Revolving Credit Facility Amended and Restated Credit Agreement	Aug. 31, 2009 Senior Unsecured Revolving Credit Facility Amended and Restated Credit Agreement	Mar. 22, 2012 Senior Unsecured Revolving Credit Facility Second Amended Restated Credit Agreement	Mar. 22, 2012 Senior Unsecured Revolving Credit Facility Second Amended Restated Credit Agreement	Mar. 22, 2012 Senior Unsecured Revolving Credit Facility Second Amended Restated Credit Agreement Minimum	Mar. 22, 2012 Senior Unsecured Revolving Credit Facility Second Amended Restated Credit Agreement Maximum	Dec. 31, 2012 Senior Unsecured Revolving Credit Facility China HR Credit Facility	Dec. 31, 2011 Senior Unsecured Revolving Credit Facility China HR Credit Facility	Dec. 31, 2007 Senior Unsecured Revolving Credit Facility Letter of Credit	Jun. 30, 2014 Senior Unsecured Revolving Credit Facility Letter of Credit Amended and Restated Credit Agreement	Mar. 22, 2012 Senior Unsecured Revolving Credit Facility Letter of Credit Second Amended Restated Credit Agreement Minimum	Mar. 22, 2012 Senior Unsecured Revolving Credit Facility Letter of Credit Second Amended Restated Credit Agreement Maximum	Jun. 30, 2014 Term Loan Facility Third Quarter	Jun. 30, 2014 Term Loan Facility Fourth Quarter	Jun. 30, 2014 Term Loan Facility Amended and Restated Credit Agreement	Aug. 31, 2009 Term Loan Facility Amended and Restated Credit Agreement	Mar. 22, 2012 Term Loan Facility Second Amended Restated Credit Agreement	Mar. 22, 2012 Term Loan Facility Second Amended Restated Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowings under senior unsecured revolving credit facility				$ 300,000	$ 325,000													$ 250,000		$ 250,000		$ 225,000			$ 5,049	$ 7,574	$ 50,000							$ 50,000		$ 100,000
Payments on borrowings on credit facilities	8,100	39,799																			172,500
Payments on borrowings on term note	4,375	3,125																																	40,000
Debt instrument maturity date																					Mar. 22, 2015														Mar. 22, 2015
Amortization payments on outstanding principal amount of term loans, in next twelve months																															2,500	2,500
Debt instrument, basis spread on variable rate									1.00%	2.50%	1.50%	3.25%	2.25%			0.50%
Fee on all outstanding amounts of letters of credit																													2.50%	3.25%
Commitment fee on the unused portion of the revolving credit facility																							0.35%	0.50%
Consolidated Leverage Ratio							300.00%
Interest Charge Coverage Ratio						300.00%
Utilized portion of credit facility																			116,600									309					85,000
Credit facility due to mature																			Mar. 22, 2015
Current portion of long-term debt and borrowings on revolving credit facilities	201,600		9,375																201,600
Credit facility, available to be utilized																	$ 108,091
Interest rate at the end of period								0.16%						3.25%	0.09%
Interest rate at the end of period, effective								3.15%