Goodwill and Intangible Assets - Goodwill (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified						3 Months Ended
Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014 Granville-Phillips [Member]	May 30, 2014 Granville-Phillips [Member]	Mar. 31, 2014 Alter S.r.l [Member]
Goodwill [Line Items]
Goodwill	$ 193,125	$ 150,909	$ 150,733	$ 41,612	$ 41,612
Acquisition purchase price adjustment						$ 381

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 25

-Paragraph 16

-URI http://asc.fasb.org/extlink&oid=34752592&loc=d3e961-128460

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