Inventories (Details) (USD $)			3 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Correction of Inventory Valuation Error [Member]
Inventories [Abstract]
Raw materials	$ 29,322,000	$ 25,754,000
Work in process	50,132,000	45,998,000
Finished goods	44,435,000	40,987,000
Total inventories	123,889,000	112,739,000
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Charge resulting from correction of error			$ 1,600,000