Goodwill and Identified Intangible Assets - Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 253,617	$ 251,044
Accumulated Amortization	(71,017)	(68,771)
Net Carrying Amount	182,600	182,273
Licensing Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	5 years	5 years
Gross Carrying Amount	3,900	3,908
Accumulated Amortization	(3,163)	(3,131)
Net Carrying Amount	737	777
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	0 years	0 years
Gross Carrying Amount	4,719	4,731
Accumulated Amortization	(4,719)	(4,731)
Net Carrying Amount	0	0
Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	12 years	12 years
Gross Carrying Amount	2,067	2,067
Accumulated Amortization	(655)	(623)
Net Carrying Amount	1,412	1,444
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	16 years	16 years
Gross Carrying Amount	22,482	21,722
Accumulated Amortization	(5,458)	(5,199)
Net Carrying Amount	17,024	16,523
Non-competes [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	3 years	3 years
Gross Carrying Amount	1,210	1,140
Accumulated Amortization	(861)	(839)
Net Carrying Amount	349	301
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	13 years	13 years
Gross Carrying Amount	165,202	163,386
Accumulated Amortization	(34,484)	(32,196)
Net Carrying Amount	130,718	131,190
Patents and acquired technology [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	15 years	15 years
Gross Carrying Amount	54,037	54,090
Accumulated Amortization	(21,677)	(22,052)
Net Carrying Amount	$ 32,360	$ 32,038