Derivative Financial Instruments Outstanding Interest Rate Swap Agreements (Details) (USD $)	12 Months Ended						12 Months Ended					12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended									9 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Interest Rate Swap 2 [Member]	Dec. 31, 2013 Interest Rate Swap 2 [Member] Notional Period 1 [Member]	Dec. 31, 2013 Interest Rate Swap 2 [Member] Notional Period 2 [Member]	Dec. 31, 2013 Interest Rate Swap 2 [Member] Notional Period 3 [Member]	Dec. 31, 2013 Interest Rate Swap 2 [Member] Notional Period 4 [Member]	Dec. 31, 2013 Interest Rate Swap 3 [Member]	Dec. 31, 2013 Interest Rate Swap 3 [Member] Notional Period 1 [Member]	Dec. 31, 2013 Interest Rate Swap 3 [Member] Notional Period 2 [Member]	Dec. 31, 2013 Interest Rate Swap 3 [Member] Notional Period 3 [Member]	Dec. 31, 2013 Interest Rate Swap 3 [Member] Notional Period 4 [Member]	Dec. 31, 2013 Interest Rate Swap 4 [Member]	Dec. 31, 2013 Interest Rate Swap 4 [Member] Notional Period 1 [Member]	Dec. 31, 2013 Interest Rate Swap 5 [Member]	Dec. 31, 2013 Interest Rate Swap 5 [Member] Notional Period 1 [Member]	Dec. 31, 2013 Interest Rate Swap 6 [Member]	Dec. 31, 2013 Interest Rate Swap 6 [Member] Notional Period 1 [Member]	Dec. 31, 2013 Interest Rate Swap 7 [Member]	Dec. 31, 2013 Interest Rate Swap 7 [Member] Notional Period 1 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 2 [Member] Notional Period 1 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 2 [Member] Notional Period 2 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 2 [Member] Notional Period 3 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 2 [Member] Notional Period 4 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 3 [Member] Notional Period 1 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 3 [Member] Notional Period 2 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 3 [Member] Notional Period 3 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 3 [Member] Notional Period 4 [Member]	Dec. 31, 2013 1-month LIBOR [Member] Interest Rate Swap 4 [Member] Notional Period 1 [Member]	Sep. 30, 2013 3-month LIBOR [Member] Interest Rate Swap 5 [Member] Notional Period 1 [Member]	Sep. 30, 2013 3-month LIBOR [Member] Interest Rate Swap 6 [Member] Notional Period 1 [Member]	Sep. 30, 2013 3-month LIBOR [Member] Interest Rate Swap 7 [Member] Notional Period 1 [Member]
Effective Date		Sep. 30, 2013					Sep. 30, 2014					Sep. 30, 2015		Sep. 30, 2016		Sep. 30, 2016		Sep. 30, 2016
Expiration Date		Sep. 29, 2014					Sep. 29, 2015					Sep. 30, 2016		Sep. 30, 2026		Sep. 30, 2026		Sep. 30, 2026
Notional Amount			$ 1,350,000,000	$ 1,300,000,000	$ 1,250,000,000	$ 1,200,000,000		$ 1,150,000,000	$ 1,100,000,000	$ 1,050,000,000	$ 1,000,000,000		$ 350,000,000		$ 100,000,000		$ 100,000,000		$ 100,000,000
Pay Fixed Rate			0.35%	0.35%	0.35%	0.35%		0.54%	0.54%	0.54%	0.54%		0.93%		2.79%		2.79%		2.80%
Receive Variable Rate																				1-month LIBOR	1-month LIBOR	1-month LIBOR	1-month LIBOR	1-month LIBOR	1-month LIBOR	1-month LIBOR	1-month LIBOR	1-month LIBOR	3-month LIBOR	3-month LIBOR	3-month LIBOR
Probable Company issued fixed rate debt	300,000,000
Probable future borrowings	$ 300,000,000