Common Stock, Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan [Member]	12 Months Ended
	Dec. 31, 2015 shares
Employee Stock Purchase Plan Disclosures [Line Items]
Discount on the fair market value of shares purchased as of the offering date (in hundredths)	5.00%
Maximum number of shares of common stock available to be purchased per participant per offering period (in shares)	125
Maximum number of shares of common stock which may be purchased under the ESPP (in shares)	734,000
Number of shares of common stock available for purchase under the ESPP (in shares)	392,704