Acquisition charges (Tables)

6 Months Ended

Jun. 30, 2014

Business Combination, Separately Recognized Transactions [Abstract]

Acquisition charges

These acquisition charges are as follows:

	For Three Months Ended June 30,				For Six Months Ended June 30,
	2014		2013		2014		2013
Amortization of intangible assets	$	79	$	81	$	159	$	162
Stock-based compensation	3		3		6		6
Retention bonuses	—		2		—		3
Acquisition charges	$	82	$	86	$	165	$	171