Share-Based Compensation - Deferred Compensation Plan (Details) - SERP	12 Months Ended
	Dec. 31, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of earned income on a pre-tax basis, deferred	25.00%
Percentage of match participants' deferrals	25.00%
Percentage of deferral in the form of common stock	15.00%
Full vest in matching contribution	3 years
Stock options authorized to issue (in shares)	1,013,000
Common stock reserved for future issuance (in shares)	400,000
Shares exercised and delivered (in shares)	13,000
Stock options vested and outstanding (in shares)	300,000