Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccruedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Schedule I - Condensed Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Total current assets	$ 142,204us-gaap_AssetsCurrent	$ 243,059us-gaap_AssetsCurrent
Total assets	2,442,474us-gaap_Assets	2,577,410us-gaap_Assets
Current liabilities:
Dividends payable	172us-gaap_DividendsPayableCurrent	17,939us-gaap_DividendsPayableCurrent	203us-gaap_DividendsPayableCurrent
Other accrued expenses	20,149us-gaap_AccruedLiabilitiesCurrent	15,264us-gaap_AccruedLiabilitiesCurrent
Total current liabilities	221,085us-gaap_LiabilitiesCurrent	252,694us-gaap_LiabilitiesCurrent
Total liabilities	1,862,939us-gaap_Liabilities	1,929,383us-gaap_Liabilities
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value-authorized, 100,000,000 shares, no shares issued or outstanding at December 31, 2014 and 2013
Common stock, $0.01 par value-authorized, 1,000,000,000 shares; 90,191,100 shares issued at December 31, 2014 and 89,900,453 shares issued at December 31, 2013	902us-gaap_CommonStockValue	899us-gaap_CommonStockValue
Additional paid-in capital	655,471	689,394
Retained earnings	33,516	1,886
Treasury stock, at cost (4,105,970 shares at December 31, 2014 and 1,500,000 shares at December 31, 2013)	(109,871)us-gaap_TreasuryStockValue	(44,163)us-gaap_TreasuryStockValue
Total stockholders' equity	579,535us-gaap_StockholdersEquity	648,027us-gaap_StockholdersEquity	442,301us-gaap_StockholdersEquity	868,143us-gaap_StockholdersEquity
Total liabilities and stockholders' equity	2,442,474	2,577,410
Parent Company [Member]
Current assets:
Cash	5,858	172
Due from wholly owned subsidiary		17,767
Total current assets	5,858	17,939
Investment in wholly owned subsidiary	580,018	648,016
Total assets	585,876	665,955
Current liabilities:
Dividends payable	172	17,939
Other accrued expenses	5,686
Total current liabilities	5,858	17,939
Total liabilities	5,858	17,939
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value-authorized, 100,000,000 shares, no shares issued or outstanding at December 31, 2014 and 2013
Common stock, $0.01 par value-authorized, 1,000,000,000 shares; 90,191,100 shares issued at December 31, 2014 and 89,900,453 shares issued at December 31, 2013	902	899
Additional paid-in capital	655,471	689,394
Retained earnings	33,516	1,886
Treasury stock, at cost (4,105,970 shares at December 31, 2014 and 1,500,000 shares at December 31, 2013)	(109,871)	(44,163)
Total stockholders' equity	580,018	648,016
Total liabilities and stockholders' equity	$ 585,876	$ 665,955