Organization and Significant Accounting Policies - Supplemental Cash Flow Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Accounting Policies [Abstract]
Interest paid, including interest capitalized	$ 25,009	$ 25,644
Income tax payments, net	1,074	70
Non-cash investing and financing activities:
Dividends and distributions payable	18,066	13,563
Conversions of redeemable common units		591
Common stock 401k matching contribution	670	639
Construction and property capital expenditure cost accruals, decrease (increase)	(3,521)	6,440
Adjustments to equity related to redeemable common units, net	$ 128	$ (737)