Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (Unaudited) - USD ($)		3 Months Ended	9 Months Ended	12 Months Ended
		Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Dividend declared (in dollars per share)		$ 0.325	$ 0.955	$ 1.2025
Deferred compensation plan held Rabbi Trust (shares)		90,588	90,588	76,745
Preferred Stock, Shares Authorized		2,000,000	2,000,000	2,000,000
Preferred Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01	$ 0.01
Stock Issued During Period, Shares, New Issues			960,488	960,488.00
Stock Issued During Period, Value, Other			$ 62.26	$ 62.26
Proceeds from Issuance of Common Stock	[1]		$ (10,000)	$ 57,360,000
Shares issued under the performance incentive plan withheld for employee taxes (shares)			10,269	12,031

[1] On September 22, 2016, we completed a public offering of 960,488 shares of our common stock at a price per share of $62.26. The net proceeds from the sale of common stock, after deducting underwriting commissions and expenses, were approximately $57.4 million.