Significant Accounting Policies - Stock Repurchase Program (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) shares
Accounting Policies [Abstract]
Stock Repurchase Program Authorization Date	Jul. 29, 2015
Share Repurchase	2,000,000
Stock Repurchase Program, Cumulative Shares Repurchased	1,216,243
Stock Repurchase Program Cumulative Cost | $	$ 10,800,000