Stock Options - Schedule of Stock Options Granted (Details) - $ / shares			9 Months Ended
	Mar. 24, 2017	Aug. 27, 2015	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Employee Stock Purchase Plan
Shares (in shares)	70,000	38,750	70,000	0
Forfeited (in shares)		(13,750)	(1,500)	(3,750)
Outstanding (in shares)		25,000	95,000	31,000	26,500	34,750
Strike Price (in dollars per share)	$ 44.21	$ 42.03	$ 44.21	$ 0.00
Vesting Period (in years)		5 years
Expiration (in years)		10 years
Tranche One
Employee Stock Purchase Plan
Shares (in shares)	46,250		46,250
Forfeited (in shares)	0
Outstanding (in shares)	46,250
Strike Price (in dollars per share)	$ 44.21
Vesting Period (in years)	3 years
Expiration (in years)	10 years
Tranche Two
Employee Stock Purchase Plan
Shares (in shares)	23,750		23,750
Forfeited (in shares)	0
Outstanding (in shares)	23,750
Strike Price (in dollars per share)	$ 44.21
Vesting Period (in years)	5 years
Expiration (in years)	10 years