Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Minimum rental commitments under non cancellable operating leases
2014	$ 24,689,000
2015	11,660,000
2016	8,001,000
2017	4,896,000
2018	1,578,000
Thereafter	7,926,000
Total	58,750,000
Minimum period of operating lease	30 days
Rental expense relating to operating leases	40,500,000	35,500,000	36,300,000
Minimum volume commitment
2014	44,365,000
2015	29,285,000
2016	15,522,000
2017	14,195,000
2018	13,829,000
Thereafter	53,954,000
Total	171,150,000
Minimum salary and bonus obligations
2014	6,984,000
2015	6,443,000
2016	5,774,000
2017	3,640,000
2018	1,200,000
Thereafter	300,000
Total	$ 24,341,000