Common and Preferred Stock Issued / Common Stock Issuable (Detail Textuals) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Mar. 22, 2016	Dec. 31, 2015
Common Stock Issued and Issuable and Preferred Stock Issued [Abstract]
Shares issued in connection with DRIP	2,938	1,564
Discount offered to employees under United has an Employee Stock Purchase Program (ESPP) to purchase shares of common stock	10.00%
Number of stock issued through ESPP	12,906	10,197
Common stock issuable shares under deferred compensation plan	520,014			458,953
Common stock, shares authorized	150,000,000			100,000,000
Shares repurchased authorized amount			$ 50.0
Number of shares repurchased under the program	764,000
Value of common stock may be repurchased	$ 36.3