Pension Plan and Employee Benefits, 401 (K) Plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
401(k) Plan [Abstract]
401 (k) Plan expense	$ 4,730	$ 4,422	$ 4,375
Other Subsidiaries [Member]
401(k) Plan [Abstract]
401 (k) Plan expense	$ 900	$ 1,000	$ 1,000