Debt - Summary of Debt Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Term note payable - domestic	$ 517,500	$ 525,000
Other debt	21,863	22,391
Total notes payable and other obligations	614,363	647,391
Securitization facility	385,000	298,000
Total notes payable, credit agreements and Securitization Facility	999,363	945,391
Current portion	507,375	460,174
Long-term portion	491,988	485,217
Revolving Credit Facility [Member] | Domestic Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit	$ 75,000	$ 100,000