Business Combinations AirSep Acquisition (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended												12 Months Ended			2 Months Ended	3 Months Ended			4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Aug. 29, 2013 AirSep [Member]	Jun. 30, 2013 AirSep [Member]	Mar. 31, 2013 AirSep [Member]	Dec. 31, 2012 AirSep [Member]	Dec. 31, 2012 AirSep [Member]	Aug. 29, 2013 AirSep [Member]	Dec. 31, 2013 AirSep [Member]	Aug. 30, 2012 AirSep [Member]
Business Acquisition [Line Items]
Standard Product Warranty Description																						five
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables																							$ 24,280
Business Acquisition, Percentage of Voting Interests Acquired																							100.00%
Goodwill	398,905							398,941					398,905	398,941	288,770								109,763
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net																							182,450
Business Acquisition, Purchase Price Allocation, Income Taxes Receivable																							2,800
Business Acquisition, Preacquisition Contingency, Amount of Settlement																							10,000
Business Acquisition, Fair Value Of Net Assets Acquired Excluding Goodwill																							72,687
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory																							34,553
Business acquisition, purchase price allocation, current assets, prepaid expenses																							615
Business acquisition, purchase price allocation, current assets, other assets																							3,837
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment																							5,342
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets																							976
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable																							13,728
Business acquisition, purchase price allocation, Customer advances and billings in excess of contract revenue																							4,782
Business acquisition, purchase price allocation, Accrued salaries																							1,837
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other																							254
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Warranty Reserve																							10,562
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Current Liabilities, Warranty Reserve																							26,471
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tangible Assets, Net																							11,969
business acquisition, purchase price allocation, current assets, deferred taxes asset																							9,262
Business Acquisition, Purchase Price Allocation, Amortizable and Unamortizable Intangible Assets																							67,000
Business Acquisition, Purchase Price Allocation, Noncurrent Liabilities, Deferred Taxes (Liability)																							15,544
Sales	303,767	301,757	[1]	298,266	[1]	273,648	[1]	303,858	[2]	254,249	239,939	216,106	1,177,438	1,014,152	794,585	14,174	29,855	27,014	31,679	40,317	71,043
Operating Income (Loss)	39,781	35,886		32,979		27,351		32,837		32,032	33,083	23,861	135,997	121,813	89,994					4,026	3,195
Business Acquisition, Amortization of Stepped Up Inventory Basis																				3,270	2,638
Amortization expense													19,230	14,792	13,376					2,285	4,570
Management Retention Expenses and Severance Costs																				1,111	2,726
Business Combination, Acquisition Related Costs																				$ 1,164

[1] During the first and second quarters of 2013, AirSep added sales of $27,014 and $29,855, respectively. During the third quarter of 2013, incremental sales related to AirSep were $14,174

[2] During the fourth quarter of 2012, AirSep added sales of $31,679.