Restatement of Condensed Consolidated Financial Statements - Summary of Adjustments to Previously Issued Consolidated Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2013 Scenario, Previously Reported [Member]	Sep. 30, 2013 Scenario, Adjustment [Member]	Sep. 30, 2013 Restated [Member]
Assets
Accounts receivable, non-affiliates	$ 39,704	$ 31,390	$ (17)	$ 31,373
Accounts receivable, affiliates	9		17	17
Deferred income taxes (non-current)	69,049	48,337	(29,718)	18,619
Equity method investments	2,028	207,566	63,133	270,699
Total assets	614,727	714,897	33,415	748,312
Liabilities and Stockholders' Equity (Deficit)
Accounts payable, accrued and other current liabilities, non-affiliates	56,371	61,033	(7,786)	53,247
Accounts payable, accrued and other current liabilities, affiliates	7		7,342	7,342
Total current liabilities	86,976	82,735	(444)	82,291
Other long-term liabilities	28,662	93,571	(72,486)	21,085
Deferred AWN capacity revenue			64,036	64,036
Total liabilities	649,410	621,088	(8,894)	612,194
Accumulated deficit	(170,279)	(51,519)	42,309	(9,210)
Total stockholders' equity (deficit)	(34,683)	93,809	42,309	136,118
Total liabilities and stockholders' equity (deficit)	$ 614,727	$ 714,897	$ 33,415	$ 748,312