Borrowings (Schedule of Borrowings) (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total borrowings	$ 1,101,889	$ 847,436
Less current portion	1,333	1,087
Less deferred debt issuance costs	4,945	5,203
Less unaccreted debt discount	1,379	1,439
Total long-term borrowings	1,094,232	839,707
4.5% Senior Notes, due December 2020
Debt Instrument [Line Items]
Total borrowings	300,000	300,000
4.2% Senior Notes, due December 2021
Debt Instrument [Line Items]
Total borrowings	350,000	350,000
Revolving Facility
Debt Instrument [Line Items]
Revolving Facility	450,000	195,000
Other borrowings
Debt Instrument [Line Items]
Other borrowings	$ 1,889	$ 2,436