Discontinued Operations - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended	9 Months Ended		3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jan. 31, 2013 Morningstar	Sep. 30, 2013 Morningstar	Sep. 30, 2014 WhiteWave Foods transaction	Dec. 31, 2012 IPO WhiteWave Foods	Jun. 30, 2013 Spinoff WhiteWave Foods	Sep. 30, 2013 Equity Swap WhiteWave Foods
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations, net of tax	$ (836,000)	$ 0	$ (836,000)	$ 2,891,000
Number Of Transactions Related To Spin-Off And Disposal							3
Sale of Stock, Percentage of Shares Offered								13.30%	66.80%	19.90%
Gain on disposition of WhiteWave common stock	0	415,783,000	0	415,783,000
Unrealized holding gains		385,600,000
Net cash proceed for full repayment of debt					1,450,000,000
Net pre-tax gain related to divestiture						871,300,000
Gain (loss) on sale of discontinued operations, net of tax	0	(398,000)	1,154,000	491,422,000		492,100,000
Discontinued operations transaction costs	$ 0		$ 0	$ 12,764,000		$ 300,000