Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 57,950	$ 36,648	$ 255,198	$ 121,339
Other comprehensive income (loss):
Unrealized gain (loss) on interest rate swaps	1,341	(890)	5,453	(5,338)
Other comprehensive income (loss), before income taxes	1,341	(890)	5,453	(5,338)
Income tax (expense) benefit	(487)	329	(2,012)	1,975
Other comprehensive income (loss), net of income taxes	854	(561)	3,441	(3,363)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	58,804	36,087	258,639	117,976
Comprehensive Loss, Net of Tax, Attributable to Noncontrolling Interest	161	0	161	0
Comprehensive income	$ 58,965	$ 36,087	$ 258,800	$ 117,976