Impairment Charges and Impairment of Joint Venture Investments - Impairment Charges on Assets or Investments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Impairment Charges And Impairment Of Joint Venture Investments [Abstract]
Assets marketed for sale or assets sold	$ 110,900	$ 179,700	$ 10,600
Total continuing operations	110,906	279,021	29,175
Sold assets – discontinued operations	0	0	8,877
Impairment of joint venture investments	0	1,909	30,652
Total impairment charges	110,900	280,900	68,800
Undeveloped Land [Member]
Impairment Charges And Impairment Of Joint Venture Investments [Abstract]
Undeveloped land previously held for development	$ 0	$ 99,300	$ 18,600