Long-Term Debt (Loss on Extinguishment of Debt) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended				3 Months Ended										6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012 Term Loans [Member]		Mar. 31, 2012 Term Loans [Member]		Mar. 31, 2011 Term Loans [Member]		Mar. 31, 2012 Senior Notes [Member]		Mar. 31, 2011 Senior Notes [Member]		Jun. 30, 2011 Senior Notes [Member]
Extinguishment of Debt [Line Items]
Face Amount Repaid/Retired			$ 183,700		$ 149,750		$ 108,200		$ 70,500		$ 110,000		$ 5,000		$ 32,300		$ 7,500
Cash Paid			184,237		153,435		108,200		70,500		110,000		5,500		35,300		8,200
Loss on extinguishment of debt	$ 2,306	$ 0	$ 4,917	[1]	$ 7,885	[1]	$ 2,300	[1]	$ 1,900	[1]	$ 2,700	[1]	$ 700	[1]	$ 4,300	[1]	$ 900	[1]

[1] Including write-off of the discount and deferred financing costs related to the debt retired.