Stock plans (Tables)

6 Months Ended

Jun. 30, 2016

Activity with respect to options for the six months ended June 30, 2016 was as follows:



	Options		Weighted Average Grant Date Fair Value		Weighted Average Grant Date Exercise Price
Options outstanding, December 31, 2015	65,401		$	7.74	$	20.17
Options exercised	(14,044	)	7.69		17.02
Options outstanding, June 30, 2016	51,357		$	7.75	$	21.03

Activity with respect to options for the six months ended June 30, 2015 was as follows:



	Options		Weighted Average Grant Date Fair Value		Weighted Average Grant Date Exercise Price
Options outstanding, December 31, 2014	1,160,057		$	7.12	$	17.74
Options exercised	(1,040,680	)	7.26		16.86
Options outstanding, June 30, 2015	119,377		$	5.94	$	25.46

Activity with respect to unvested restricted share awards for the six months ended June 30, 2016 was as follows:



	Restricted Share Awards		Weighted Average Grant Date Fair Value
Restricted share awards outstanding, December 31, 2015	2,739,446		$	38.25
Restricted share awards granted	534,905		48.69
Restricted share awards vested	(783,523	)	37.32
Restricted share awards forfeited	(8,317	)	37.94
Restricted share awards outstanding, June 30, 2016	2,482,511		$	40.79

Activity with respect to unvested restricted share awards for the six months ended June 30, 2015 was as follows:



	Restricted Share Awards		Weighted Average Grant Date Fair Value
Restricted share awards outstanding, December 31, 2014	2,858,711		$	35.81
Restricted share awards granted	670,432		43.55
Restricted share awards vested	(781,704	)	34.42
Restricted share awards forfeited	(51,818	)	38.04
Restricted share awards outstanding, June 30, 2015	2,695,621		$	38.09

Activity with respect to unvested restricted share units for the six months ended June 30, 2016 was as follows:



	Restricted Share Units		Weighted Average Grant Date Fair Value
Restricted share units outstanding, December 31, 2015	114,337		$	38.47
Restricted share units granted	20,129		48.69
Restricted share units vested	(23,982	)	38.18
Restricted share units issued in lieu of cash dividends	1,629		38.47
Restricted share units outstanding, June 30, 2016	112,113		$	40.37

Activity with respect to unvested restricted share units for the six months ended June 30, 2015 was as follows:



	Restricted Share Units		Weighted Average Grant Date Fair Value
Restricted share units outstanding, December 31, 2014	103,484		$	36.54
Restricted share units granted	28,057		42.91
Restricted share units vested	(19,455	)	34.58
Restricted share units issued in lieu of cash dividends	1,517		36.53
Restricted share units forfeited	(892	)	35.42
Restricted share units outstanding, June 30, 2015	112,711		$	38.47

Activity with respect to unvested performance share awards for the six months ended June 30, 2016 was as follows:



	Performance Share Awards		Weighted Average Grant Date Fair Value
Performance share awards outstanding, December 31, 2015	172,594		$	40.70
Performance share awards granted	121,844		48.69
Performance share awards vested	(57,581	)	36.11
Performance share awards conversion adjustment	45,517		36.82
Performance share awards outstanding, June 30, 2016	282,374		$	44.46

Activity with respect to unvested performance share awards for the six months ended June 30, 2015 was as follows:



	Performance Share Awards		Weighted Average Grant Date Fair Value
Performance share awards outstanding, December 31, 2014	106,369		$	36.03
Performance share awards granted	81,569		45.03
Performance share awards vested	(15,344	)	31.38
Performance share awards outstanding, June 30, 2015	172,594		$	40.70

The breakdown of share compensation expenses by award type for the periods indicated was as follows: