Supplemental Cash Flow Information - Supplemental Cash Flow Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			12 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013
Net cash provided from operating activities included:
Income taxes (refunded) paid to taxing authorities	$ 39		$ (162)
Interest paid	55,190		37,541
Non-cash investing and financing activities included:
Asset retirement costs capitalized, net	3,218	[1]	1,690	76,373	[1]
Increase in accrued capital expenditures	$ 6,808		$ 128,136

[1] Includes cost incurred whether capitalized or expensed.