Basis of Presentation - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 31, 2011	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2012 Forecasted [Member]	Sep. 30, 2011 Correction [Member]
Basis Of Presentation [Line Items]
Restructuring charges		$ 3,056		$ 839	$ 9,018	$ 2,977	$ 12,971
Estimated Profit Enhancement Plan implementation costs								0
Fixed exchange ratio of shares	0.5
Legal, professional and other costs incurred in response to unsolicited tender offer		1,206	2,227	0	43,331	0
Total cost paid					43,010
Increase to current deferred income tax assets	43,032	45,353	43,032	48,743	45,353	48,743	43,032		910
Increase to prepaid income taxes	21,598	26,384	21,598	27,809	26,384	27,809	21,598		735
Increase to current income taxes payable	167,560	213,735	167,560	239,438	213,735	239,438	167,560		16,676
Decrease to non current deferred income tax liabilities	732,528	680,880	732,528	794,921	680,880	794,921	732,528		(5,849)
Decrease to retained earnings	$ 1,334,476	$ 1,274,465	$ 1,334,476	$ 1,363,640	$ 1,274,465	$ 1,363,640	$ 1,334,476		$ (9,182)