ValveXchange (Details) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 31, 2011	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2012
Schedule of Cost-method Investments [Line Items]
Preferred stock, written down investment				$ 3,229,000
Other non-operating expense recorded to write-down long-term note receivable from ValveXchange		$ 2,000,000
ValveXchange, Inc. [Member]
Schedule of Cost-method Investments [Line Items]
Loans receivable, revolving credit line, expiration date			Jul. 30, 2018
Loans receivable, revolving credit line, interest rate	8.00%
Amount of note receivable					$ 2,000,000
Notes, Loans and Financing Receivable, Net, Noncurrent		0	$ 0
ValveXchange, Inc. [Member] | Revolving Credit Facility [Member]
Schedule of Cost-method Investments [Line Items]
Loans receivable, revolving credit line, maximum capacity	$ 2,000,000
Series A Junior Participating Preferred Stock [Member] | ValveXchange, Inc. [Member]
Schedule of Cost-method Investments [Line Items]
Preferred stock purchased, value	$ 3,500,000
Preferred stock carrying value		$ 0	$ 0