Supplemental Guarantor Financial Information (Condensed Consolidating Statements Of Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	$ 241,945	$ 228,819	$ 207,984	$ 197,738	$ 198,360	$ 199,029	$ 192,020	$ 191,040	$ 876,486	$ 780,449	$ 624,576
Operating costs and expenses									793,885	689,942	547,301
Operating (loss) income									82,601	90,507	77,275
Interest expense, net, including amortization of deferred financing costs and note discount									23,086	22,057	21,109
Other expense (income), net									(3,150)	(1,821)	(804)
Income (loss) before income taxes									62,665	70,271	56,970
Income tax expense (benefit)									42,018	27,009	(13,176)
Net income (loss)	5,716	(8,982)	14,765	9,148	10,934	12,706	9,579	10,043	20,647	43,262	70,146
Net (loss) income attributable to noncontrolling interests									(3,169)	(329)	(87)
Net income attributable to controlling interests and available to common stockholders	7,467	(8,408)	15,327	9,430	11,201	12,897	9,664	9,829	23,816	43,591	70,233
Other comprehensive income (loss), attributable to controlling interest									32,096	(21,292)	(18,630)
Other comprehensive income (loss) attributable to controlling interests									55,912	22,299	51,603
Elimination [Member]
Revenues									(8,782)	(10,176)	(4,388)
Operating costs and expenses									(8,362)	(9,230)	(4,409)
Operating (loss) income									(420)	(946)	21
Equity in (earnings) losses of subsidiaries									81,375	71,102	39,849
Other expense (income), net										(557)
Income (loss) before income taxes									(81,795)	(71,491)	(39,828)
Net income (loss)									(81,795)	(71,491)	(39,828)
Net (loss) income attributable to noncontrolling interests									(3,169)	(329)	(87)
Net income attributable to controlling interests and available to common stockholders									(78,626)	(71,162)	(39,741)
Other comprehensive income (loss), attributable to controlling interest									(35)	(109)	219
Other comprehensive income (loss) attributable to controlling interests									(78,661)	(71,271)	(39,522)
Parent [Member]
Operating costs and expenses									12,583	11,366	9,604
Operating (loss) income									(12,583)	(11,366)	(9,604)
Interest expense, net, including amortization of deferred financing costs and note discount									10,357	(541)	(940)
Equity in (earnings) losses of subsidiaries									(87,874)	(78,992)	(47,421)
Other expense (income), net									5,453	8	(19,252)
Income (loss) before income taxes									59,481	68,159	58,009
Income tax expense (benefit)									38,414	24,508	(12,116)
Net income (loss)									21,067	43,651	70,125
Net income attributable to controlling interests and available to common stockholders									21,067	43,651	70,125
Other comprehensive income (loss), attributable to controlling interest									(11,151)	14,536	10,687
Other comprehensive income (loss) attributable to controlling interests									9,916	58,187	80,812
Guarantors [Member]
Revenues									665,709	636,328	505,716
Operating costs and expenses									554,235	529,924	417,762
Operating (loss) income									111,474	106,404	87,954
Interest expense, net, including amortization of deferred financing costs and note discount									11,137	21,546	18,084
Equity in (earnings) losses of subsidiaries									6,499	7,890	7,572
Other expense (income), net									(3,519)	(4,529)	15,714
Income (loss) before income taxes									97,357	81,497	46,584
Income tax expense (benefit)									3,603	2,561	(1,060)
Net income (loss)									93,754	78,936	47,644
Net income attributable to controlling interests and available to common stockholders									93,754	78,936	47,644
Other comprehensive income (loss), attributable to controlling interest									39,646	(38,689)	(29,405)
Other comprehensive income (loss) attributable to controlling interests									133,400	40,247	18,239
Non-Guarantors [Member]
Revenues									219,559	154,297	123,248
Operating costs and expenses									235,429	157,882	124,344
Operating (loss) income									(15,870)	(3,585)	(1,096)
Interest expense, net, including amortization of deferred financing costs and note discount									1,592	1,052	3,965
Other expense (income), net									(5,084)	3,257	2,734
Income (loss) before income taxes									(12,378)	(7,894)	(7,795)
Income tax expense (benefit)									1	(60)
Net income (loss)									(12,379)	(7,834)	(7,795)
Net income attributable to controlling interests and available to common stockholders									(12,379)	(7,834)	(7,795)
Other comprehensive income (loss), attributable to controlling interest									3,636	2,970	(131)
Other comprehensive income (loss) attributable to controlling interests									$ (8,743)	$ (4,864)	$ (7,926)