Income Taxes - Reconciliation of Income Tax Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Computed income tax expense at statutory federal income tax rate of 35%	$ 14,450	$ 9,670	$ 8,096
State income taxes, net of federal provision	227	345	470
Foreign tax rate differentials	(1,262)	77	(2,031)
U.S. tax on foreign earnings U.S. tax on foreign earnings (net of foreign tax credits)	(2,168)	(1,831)	(595)
Change in valuation allowance	(11,650)	(2,184)	14,220
Proceeds from life insurance	(133)	(196)	(472)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(1,401)	1,664	(371)
Other, net	2,046	765	261
Income tax expense	$ 109	$ 8,310	$ 19,578
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Computed income tax expense at statutory federal income tax rate of 35%, tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal provision, tax rate	0.50%	1.20%	2.00%
Foreign tax differentials rate	(3.10%)	0.30%	(8.80%)
U.S. tax on foreign earnings rate	(5.30%)	(6.60%)	(2.60%)
Change in valuation allowance, tax rate	(28.20%)	(7.90%)	61.50%
Proceeds from life insurance rate	(0.30%)	(0.70%)	(2.00%)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Percent	(3.40%)	6.00%	(1.60%)
Other, net, tax rate	5.00%	2.80%	1.10%
Income tax expense	0.20%	30.10%	84.60%