Long-Term Debt (Indebtedness Table) (Details) (USD $) In Thousands, unless otherwise specified										12 Months Ended		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Line of Credit [Member] 2016	Dec. 31, 2012 Line of Credit [Member] 2016	Dec. 31, 2013 CEI Credit Facility [Member]	Dec. 31, 2012 CEI Credit Facility [Member] 2016	Feb. 02, 2014 Unsecured Debt [Member] 2022	Dec. 31, 2013 Other Debt Obligations [Member]	Dec. 31, 2012 Other Debt Obligations [Member] 2016	Dec. 31, 2013 Four Point Three Percent [Member] Line of Credit [Member] 2016	Dec. 31, 2012 Four Point Three Percent [Member] Line of Credit [Member] 2016	Sep. 30, 2013 Four Point Three Percent [Member] CEI Credit Facility [Member] 2016	Dec. 31, 2013 Eight Point Eight Seven Five Percent [Member] Unsecured Debt [Member] 2018	Dec. 31, 2012 Eight Point Eight Seven Five Percent [Member] Unsecured Debt [Member] 2018	Dec. 31, 2013 Seven Point One Two Five Percent [Member] Unsecured Debt [Member] 2022	Dec. 31, 2012 Seven Point One Two Five Percent [Member] Unsecured Debt [Member] 2022
Debt Instrument [Line Items]
Long-term Debt	$ 1,200,472	$ 1,036,305	$ 155,000	$ 71,000	$ 65,041	$ 0	$ 196,500	$ 13,229	$ 0				$ 717,202	$ 715,305	$ 250,000	$ 250,000
Line of Credit Facility, Interest Rate During Period										3.15887%	4.30%	5.30%
Percentage bearing fixed interest rate													8.875%		7.125%
Debt Instrument, Unamortized Discount													$ 7,800	$ 9,700