Shareholders' Equity - Accumulated Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (79,477)	$ (54,117)	$ (39,684)
Other comprehensive loss	(7,467)	(25,360)	(14,433)
Accumulated other comprehensive loss	(86,944)	(79,477)	(54,117)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(4,677)	1,290	3,900
Other comprehensive loss	1,873	(5,967)	(2,610)
Accumulated other comprehensive loss	(2,804)	(4,677)	1,290
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(179)	(145)	(182)
Other comprehensive loss	38	(34)	37
Accumulated other comprehensive loss	(141)	(179)	(145)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(74,621)	(55,262)	(43,402)
Other comprehensive loss	(9,378)	(19,359)	(11,860)
Accumulated other comprehensive loss	$ (83,999)	$ (74,621)	$ (55,262)