Disclosure of Supplemental Cash Flow Information (Detail) - Disclosure of Supplemental Cash Flow Information (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest paid	$ 7,295	$ 5,081	$ 1,672
Income taxes paid (refunded)	6,940	9,159	(36,355)
Fair value of CTI assets acquired		217,015
Fair value of CTI liabilities acquired		57,159
Cash paid		159,856
Less: Cash acquired		11,097
Net cash paid for CTI acquisition		$ 148,759