DEBT OBLIGATIONS AND CREDIT FACILITIES - Debt Obligations (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
5.03% [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 75,000
Debt Instrument, Offering Date	Jun. 30, 2004
Debt Instrument, Maturity Date	Jun. 14, 2008
Debt Instrument, Payment Terms	$75,000, 5.03%, issued in June 2004, payable in seven equal annual installments starting June 14, 2008
Debt Instrument, Interest Rate, Stated Percentage	5.03%
6.09% [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	50,000
Debt Instrument, Offering Date	Jun. 30, 2006
Debt Instrument, Maturity Date	Jun. 06, 2016
Debt Instrument, Payment Terms	$50,000, 6.09%, issued in June 2006, payable on June 6, 2016
Debt Instrument, Interest Rate, Stated Percentage	6.09%
5.82% [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	50,000
Debt Instrument, Offering Date	Nov. 30, 2006
Debt Instrument, Maturity Date	Nov. 08, 2016
Debt Instrument, Payment Terms	$50,000, 5.82%, issued in November 2006, payable on November 8, 2016
Debt Instrument, Interest Rate, Stated Percentage	5.82%
6.75% [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	250,000
Debt Instrument, Offering Date	Nov. 30, 2009
Debt Instrument, Maturity Date	Dec. 02, 2019
Debt Instrument, Payment Terms	$250,000, 6.75%, issued in November 2009, payable on December 2, 2019
Debt Instrument, Interest Rate, Stated Percentage	6.75%
2.50% [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	250,000
Debt Instrument, Loan Amortization Rate	2.50%
Debt Instrument, Offering Date	Dec. 31, 2012
Debt Instrument, Maturity Date	Dec. 21, 2017
Debt Instrument, Payment Terms	$250,000, rate as described below, term loan issued in December 2012, payable 2.5% per quarter through September 2017, final $125,000 payment on December 21, 2017
Fixed interest rate as a result of interest rate swap	2.60%
Final principal payment	$ 125,000