Contingencies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2016 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Local tax assessment period, beginning date	Jun. 01, 2005
Local tax assessment period, ending date	May 31, 2015
Proposed underpaid tax, applicable interest and penalties amount	$ 1,439,452
Local tax assessment, estimated probable loss	$ 391,000