Fair Value Measurements (Restated) - Schedule of Valuation Techniques to Measure Fair Value of Instruments and Significant Unobservable Inputs and Values (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Estimated fair value	$ 266,000
Discounted Cash Flow [Member] | Investment in AWN [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Estimated fair value	266,000
Valuation Technique	Discounted Cash Flow
Discounted Cash Flow [Member] | Investment in AWN [Member] | Weighted Average Cost of Capital [Member] | Minimum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	7.80%
Discounted Cash Flow [Member] | Investment in AWN [Member] | Weighted Average Cost of Capital [Member] | Maximum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	11.50%
Discounted Cash Flow [Member] | Investment in AWN [Member] | Annual cash flow projections [Member] | Minimum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, amount	50,000
Discounted Cash Flow [Member] | Investment in AWN [Member] | Annual cash flow projections [Member] | Maximum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, amount	65,000
Discounted Cash Flow [Member] | Investment in AWN [Member] | Non-controlling interest discount [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	0.00%
Cost / Replacement Value [Member] | Deferred AWN Capacity Revenue [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Estimated fair value	$ 68,182
Valuation Technique	Cost / Replacement Value
Cost / Replacement Value [Member] | Deferred AWN Capacity Revenue [Member] | Weighted Average Cost of Capital [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	11.50%
Cost / Replacement Value [Member] | Deferred AWN Capacity Revenue [Member] | Cost trend factor [Member] | Minimum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	1.00%
Cost / Replacement Value [Member] | Deferred AWN Capacity Revenue [Member] | Cost trend factor [Member] | Maximum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	2.17%
Cost / Replacement Value [Member] | Deferred AWN Capacity Revenue [Member] | Estimated % used by AWN [Member] | Minimum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	4.00%
Cost / Replacement Value [Member] | Deferred AWN Capacity Revenue [Member] | Estimated % used by AWN [Member] | Maximum [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Significant Input Values, rate	100.00%
Cost / Replacement Value [Member] | Deferred AWN Capacity Revenue [Member] | Historical cost of underlying assets [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Historical Cost of underlying assets	Actual cost