Inventory and Other Current Assets Additional Information (Details) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Available-for-sale Securities [Abstract]
Available-for-sale securities, net unrealized holding gain (loss) reversed following sale		$ 1,200,000
Available-for-sale securities, unrealized holding gain (loss) reversed following sale		1,800,000
Number of shares comprising Available for Sale Securities				1.4
Available-for-sale Securities, Income Tax Expense on Change in Unrealized Holding Gain (Loss)		600,000	200,000
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax			700,000
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) before Taxes			500,000
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	10,600,000
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		(1,153,000)
Available-for-sale Securities, Current				$ 8,800,000