Supplemental Financial Information - Noncash Investing and Financing Activities (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012
Supplemental Cash Flow Information [Abstract]
Interest Paid, Net	$ 8.9	$ 31.9
Interest on Internal Revenue Service Assessment		$ 0.2

The amount of cash paid for interest during the period net of cash paid for interest that is capitalized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

Name:	us-gaap_InterestPaidNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration