Employee Pension Plans (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Summary of net periodic benefit cost
Interest cost	$ 1,011,000	$ 1,030,000
Expected return on plan assets	(1,256,000)	(1,192,000)
Amortization of net loss	1,460,000	1,077,000
Net periodic benefit cost	1,215,000	915,000
Company contribution	900,000	600,000
Expected contributions remainder of current fiscal year	$ 1,800,000