Incentive Plans - Summary of Impact of Fund Interests and Other Similar Deferred Compensation Arrangements (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share Based Compensation [Abstract]
Amortization, net of forfeitures	$ 62,197	$ 41,209	$ 14,551
Change in the fair value of underlying investments	14,099	7,557	(3,024)
Total	$ 76,296	$ 48,766	$ 11,527

Costs and payments related to employee benefits and equity-based compensation, such as pension expense and contributions, other postretirement benefits expense and payments, stock or unit options expense, and amortization of restricted stock or unit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration