Accrued Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Accrued Liabilities [Line Items]
Accrued compensation	$ 38,801	$ 33,312
Accrued insurance	31,146	30,376
Accrued taxes	11,870	28,310
Accrued interest	9,045	9,037
Accrued professional services liabilities	6,930	2,011
Accrued product reimbursement	10,225	9,361
Accrued liabilities-other	27,304	28,114
Total accrued liabilities	$ 135,321	$ 140,521