Derivative Instruments - Derivative Narrative (Details) (USD $)	12 Months Ended				9 Months Ended					3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Oct. 10, 2012 Interest Rate Swap [Member] Cash Flow Hedging [Member]	Oct. 10, 2012 Interest Rate Swap [Member] Designated as Hedging Instrument [Member]	Dec. 31, 2011 Interest Rate Swap [Member] Not Designated as Hedging Instrument [Member] July 2011 Maturity [Member]	Dec. 31, 2011 Interest Rate Swap [Member] Not Designated as Hedging Instrument [Member] Q1 2011 Maturity [Member]	Dec. 31, 2012 Senior Secured Term Loan A [Member] Interest Rate Swap [Member] Cash Flow Hedging [Member]	Dec. 31, 2012 Senior Secured Term Loan B [Member] Interest Rate Swap [Member] Cash Flow Hedging [Member]	Dec. 31, 2012 Interest Rate Swap [Member] Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred										$ 500,000
Notional Amount of Cash Flow Hedge Instruments				100,000,000				175,000,000	150,000,000
Derivative, Fixed Interest Rate				1.80%				0.738%	2.0525%
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion					1,000,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	1,000,000	100,000	900,000		600,000
Notional Amount of Other Derivatives Not Designated as Hedging Instruments						$ 125,000,000	$ 75,000,000