Condensed Consolidated Statements of Stockholders' Deficit (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement Of Stockholders Equity [Abstract]
Cash dividend per share	$ 0	$ 0.225	$ 0.225	$ 0.45