Supplemental Guarantor Information (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Statement of Income Captions [Line Items]
NET INCOME	$ 42,602	$ 32,042	$ 69,059	$ 55,569
Other comprehensive (loss) income, net:
Amortization of actuarial loss on defined benefit pension plan, net	4	4	72	9
Unrealized (loss) gain on marketable securities, available-for-sale, net	(150)	236	(169)	424
Other comprehensive (loss) income, net	(146)	240	(97)	433
Comprehensive income	42,456	32,282	68,962	56,002
REPORTABLE LEGAL ENTITIES | TRG, INC.
Condensed Statement of Income Captions [Line Items]
NET INCOME	42,602	32,042	69,059	55,569
Other comprehensive (loss) income, net:
Amortization of actuarial loss on defined benefit pension plan, net	4	4	51	9
Unrealized (loss) gain on marketable securities, available-for-sale, net	(150)	236	(169)	424
Other comprehensive (loss) income, net	(146)	240	(118)	433
Comprehensive income	42,456	32,282	68,941	56,002
REPORTABLE LEGAL ENTITIES | GUARANTOR SUBSIDIARIES
Condensed Statement of Income Captions [Line Items]
NET INCOME	18,780	14,931	30,017	25,624
Other comprehensive (loss) income, net:
Amortization of actuarial loss on defined benefit pension plan, net	0	0	16	0
Unrealized (loss) gain on marketable securities, available-for-sale, net	0	0	0	0
Other comprehensive (loss) income, net	0	0	16	0
Comprehensive income	18,780	14,931	30,033	25,624
REPORTABLE LEGAL ENTITIES | NON-GUARANTOR SUBSIDIARIES
Condensed Statement of Income Captions [Line Items]
NET INCOME	5,619	(1,171)	8,897	(2,041)
Other comprehensive (loss) income, net:
Amortization of actuarial loss on defined benefit pension plan, net	0	0	5	0
Unrealized (loss) gain on marketable securities, available-for-sale, net	0	0	0	0
Other comprehensive (loss) income, net	0	0	5	0
Comprehensive income	5,619	(1,171)	8,902	(2,041)
GUARANTOR ELIMINATIONS
Condensed Statement of Income Captions [Line Items]
NET INCOME	(24,399)	(13,760)	(38,914)	(23,583)
Other comprehensive (loss) income, net:
Amortization of actuarial loss on defined benefit pension plan, net	0	0	0	0
Unrealized (loss) gain on marketable securities, available-for-sale, net	0	0	0	0
Other comprehensive (loss) income, net	0	0	0	0
Comprehensive income	$ (24,399)	$ (13,760)	$ (38,914)	$ (23,583)