Stock Based Compensation (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($) item shares	Jun. 30, 2014 USD ($) shares
Stock-based compensation
Number of stock-based employee compensation plans | item	4
Number of executive stock award plans | item	3
Outstanding stock options (in shares)	0	0
Total unrecognized compensation cost related to non-vested share-based compensation arrangements | $	$ 6,380
Weighted-average period over which unrecognized compensation cost is expected to be recognized	3 years 3 months 20 days
Stock options
Stock-based compensation
Total fair value of options vested and expensed | $	$ 0	$ 0
Outstanding stock options (in shares)	0	0
Stock options exercised (in shares)	0	0