XML 48 R40.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value of Long-Term Debt - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Carrying value of long-term debt $ 1,821,238us-gaap_LongTermDebt $ 1,822,997us-gaap_LongTermDebt
Fair value of long-term debt $ 1,835,398us-gaap_LongTermDebtFairValue $ 1,790,987us-gaap_LongTermDebtFairValue