Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2009 Internal Revenue Service (IRS) [Member] Settlement with Taxing Authority [Member]	Jun. 30, 2013 Internal Revenue Service (IRS) [Member] Settlement with Taxing Authority [Member]	Dec. 31, 2012 Internal Revenue Service (IRS) [Member] Settlement with Taxing Authority [Member]	Jun. 30, 2013 Prior Period Adjustment [Member]
Summary of Significant Accounting Policies [Line Items]
Depreciation and other amortization	$ 26,179	$ 26,133	$ 50,307	$ 53,539				$ 1,561
Period to carry back net operating losses						up to 5 years
IRS tax refund					40,418
Refunds in excess are required to be reviewed by Joint Committee on Taxation						2,000
Agreed refund adjustment to taxable income							13,700
Taxes owed							4,806
Accrued interest							490
Preferred stock distributions taxable as capital gain			$ 221				$ 8,238