Capital Stock - Additional Information (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Repurchase Program	Jun. 30, 2014 Repurchase Program	Jun. 18, 2013 Repurchase Program	Dec. 31, 2012 2012 Program
Class Of Stock [Line Items]
Common stock available for sale	200,000,000	200,000,000				10,000,000
Common stock share authorized to repurchase					10,000,000
Stock repurchased during period, shares			0	100,000
Stock repurchased during period, value	$ 1,912		$ 0	$ 1,912