Goodwill and Other Intangible Assets, Net - Components of Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Schedule Of Acquired Finite And Indefinite Lived Intangible Asset By Major Class [Line Items]
Total definite and indefinite life intangible assets, gross, excluding goodwill	$ 45,929	$ 76,552
Total gross definite life intangible assets	33,744	64,367
Total indefinite life intangible assets	12,185	12,185
Total indefinite life intangible assets	12,185	12,185
Accumulated Amortization	26,550	56,232
Total definite and indefinite life intangible assets, net, excluding goodwill	19,379	20,320
Net definite life intangible assets	7,194	8,135
Weighted Average Remaining Life	3 years	4 years 4 months 24 days
Patents [Member]
Schedule Of Acquired Finite And Indefinite Lived Intangible Asset By Major Class [Line Items]
Total gross definite life intangible assets	6,905	36,347
Accumulated Amortization	5,342	35,047
Net definite life intangible assets	1,563	1,300
Weighted Average Remaining Life	2 years 6 months	4 years 10 months 24 days
Acquired intangibles [Member]
Schedule Of Acquired Finite And Indefinite Lived Intangible Asset By Major Class [Line Items]
Total gross definite life intangible assets	22,592	20,770
Accumulated Amortization	19,292	16,778
Net definite life intangible assets	3,300	3,992
Weighted Average Remaining Life	2 years 8 months 12 days	3 years 7 months 6 days
Noncompete agreements [Member]
Schedule Of Acquired Finite And Indefinite Lived Intangible Asset By Major Class [Line Items]
Total gross definite life intangible assets	1,790	3,418
Accumulated Amortization	876	2,169
Net definite life intangible assets	914	1,249
Weighted Average Remaining Life	2 years	2 years 9 months 18 days
All other [Member]
Schedule Of Acquired Finite And Indefinite Lived Intangible Asset By Major Class [Line Items]
Total gross definite life intangible assets	2,457	3,832
Accumulated Amortization	1,040	2,238
Net definite life intangible assets	1,417	1,594
Weighted Average Remaining Life	5 years 2 months 12 days	7 years 2 months 12 days
Trade names [Member]
Schedule Of Acquired Finite And Indefinite Lived Intangible Asset By Major Class [Line Items]
Total indefinite life intangible assets	10,685	10,685
Total indefinite life intangible assets	10,685	10,685
Horizon license [Member]
Schedule Of Acquired Finite And Indefinite Lived Intangible Asset By Major Class [Line Items]
Total indefinite life intangible assets	1,500	1,500
Total indefinite life intangible assets	$ 1,500	$ 1,500