Debt - Summary of Total Outstanding Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Short-Term Debt:
Total Short-Term Borrowings	$ 40,000
Long-Term Debt:
Total Long-Term Borrowings	320,000	340,000
Revolving Credit Facility [Member]
Short-Term Debt:
Total Short-Term Borrowings
Term Loan [Member]
Short-Term Debt:
Total Short-Term Borrowings	40,000
Long-Term Debt:
Total Long-Term Borrowings	$ 320,000