Consolidated Statements of Redeemable Noncontrolling Interest and Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Statement Of Stockholders Equity [Abstract]
Common stock issued, per share	$ 215.00	$ 242
Common stock secondary public offering issuance costs	$ 14,595	$ 11,122